RUSSIA-UKRAINE LATEST
* How Putin's invasion has backfired
* Ukrainian tries to scuttle Russian boss's superyacht
* Russian ruble plummets as sanctions bite
* Russia to be excluded from sports including Fifa World Cup

Ukrainian officials have confirmed at least 70 soldiers were killed in a Russian airstrike on their military base on Sunday.

The attack took place at Okhtyrka, in the Sumy region which is currently under siege by Russian forces. Emergency workers were still sifting through rubble trying to find survivors, BBC is reporting.

A 64km convoy of Russian tanks and other vehicles threatened Ukraine's capital tonight, as an intense shelling attack targeted the country's second-largest city and both sides looked to resume talks in the coming days aimed at stopping the fighting. 

The country's embattled president said he believed the stepped-up shelling was designed to force him into concessions. 

"I believe Russia is trying to put pressure (on Ukraine) with this simple method," Ukrainian President Volodymyr Zelenskyy said today in a video address. 

He did not offer details of hourslong talks that took place Monday, but he said Kyiv was not prepared to make concessions "when one side is hitting another with rocket artillery." 

US satellite-imaging company Maxar Technologies said the convoy contained hundreds of armoured vehicles, tanks, towed artillery and logistics support vehicles. The images are from Monday. 

In the sporting world, World Taekwondo has stripped Putin of his honorary taekwondo black belt. Russian teams have been suspended from all international soccer matches as well as from all international rugby "until further notice". 

This satellite image provided by Maxar Technologies shows the northern end of a convoy at the southeast of Ivankiv, northwest of Kyiv, Ukraine. Photo / AP 

Ukraine's representative to the UN has told the world: "Do not listen to Russia's lies, listen to Ukraine's cries. We need your help." 

The plea came during an emergency meeting of the UN's Security Council in which the scale of the humanitarian crisis was revealed and as claims emerge that Russia has dropped a devastating bomb on Ukrainian territory. 

Sergiy Kyslytsya spoke on the last day of Russia's tenure as President of the security council in a meeting when member states claimed that Russia was using illegal cluster munitions. 

UN refugee chief Filippo Grandi issued a warning over the scale of the growing refugee crisis, commending those countries admitting refugees but saying he was concerned that the exodus was only "the beginning". 

He said the UNHCR was making plans based on up to 4 million Ukrainians crossing borders in the coming days and weeks. 

He called on world governments to donate to the relief effort, to add to nearly US$40 million in private donations made in recent days. 

Reuters reports that Ukrainian ambassador to the United States, Oksana Markarova, has claimed that Russia used a vacuum bomb during the conflict. 

Vacuum bombs are thermobaric weapons that create mass destruction by sucking oxygen from the air to create a high-temperature explosion. 

The weapons, often referred to as the "Father Of All Bombs" are banned by the Geneva Convention and cause devastating injuries, literally sucking the air from the lungs of anyone nearby and causing a huge shockwave. 

"The devastation that Russia is trying to inflict on Ukraine is large," said Markarova. "They should pay, they should pay a heavy price." 

Andreea Irimca from Moldova joins others to protest in Pamplona, northern Spain, Monday, Feb. 28, 2022, after the Russian invasion of Ukraine. Photo / AP 

In the Security Council, Russia's representative Vasily Nebenzya said that the Ukrainian people were being held hostage by "radicals" and claimed that civilians were being protected in areas now held by Russia. 

He also claimed that Ukraine's decision to release prisoners to fight has led to looting. 

He told Kyiv's residents that they were free to leave, saying they would be given safe passage. 

He claimed that "dirty lies" were being spread by Ukraine and amplified by Western media, telling the council that Ukraine was placing forces in civilian areas and Russia was not targeting civilians. 

Ukraine's representative Sergiy Kyslytsya replied that the invasion "violates the conscience of the world". 

He said that Russia was attacking kindergartens, hospitals and mobile aid brigades. 

"The is the action of a state determined to kill civilians," he said. 

He warned that Russia was training its missiles on targets that, if struck, could lead to radioactive fallout. 

That claim came as the United Nations' nuclear watchdog said missiles have hit a radioactive waste disposal site in the Ukrainian capital of Kyiv. 

Kyslytsya urged the world to ignore what he said were consistent mistruths spread by Russia's representatives. 

"Do not listen to Russia's lies, listen to Ukraine's cries. We need your help." 

His comments to the Security Council came after Kyslytsya made an impassioned speech to the General Assembly where he told Putin that his nuclear threats were suicidal, referencing Adolf Hitler's death in 1945. 

Ukraine welcomes volunteers, Kyiv under threat 

Ukraine's President Volorymyr Zelenskyy has signed a decree temporarily lifting the requirement for entry visas for any foreigner willing to join Ukraine's International Defence Legion and fight on Ukraine's side against invading Russian troops. 

The decree takes effect Tuesday and will remain in effect as long as martial law is in place. 

The brutal invasion of Ukraine rages on with blasts rocking Russia's two main targets in Kyiv and Kharkiv — cities Putin reportedly ordered the military to take by force today. 

Russian forces shelled Kharkiv on Monday, rocking a residential neighbourhood, and closed in on Kyiv, in a 27km convoy of hundreds of tanks and other vehicles, as talks aimed at stopping the fighting yielded only an agreement to keep talking. 

Zelenskyy said the stepped-up shelling was aimed at forcing him into concessions. 

"I believe Russia is trying to put pressure [on Ukraine]," he said. 

He did not offer details of the earlier talks, but said that Kyiv was not prepared to make concessions "when one side is hitting each other with rocket artillery". 

This satellite image provided by Maxar Technologies shows the southern end of a convoy, east of Antonov airport, Ukraine, Monday Feb. 28, 2022. Photo / Maxar Technologies/AP 

Amid ever-growing international condemnation, Russia found itself increasingly isolated five days into its invasion, facing unexpectedly fierce resistance in Ukraine and economic havoc at home. 

For the second day in a row, the Kremlin raised the spectre of nuclear war, announcing that its nuclear-capable intercontinental ballistic missiles, submarines and long-range bombers had all been put on high alert, following Putin's orders over the weekend. 

Putin denounced the US and its allies as an "empire of lies". 

Meanwhile, an embattled Ukraine moved to solidify its ties to the West by applying to join the European Union — a largely symbolic move for now, but one that is unlikely to sit well with Putin, who has long accused the US of trying to pull Ukraine out of Moscow's orbit. 

Zelenskyy also announced that all prisoners who have real combat experience will be released from jail and will be able to "compensate for their guilt in the hottest spots of war". 

"We have taken a decision which is not easy from the moral point of view, but which is useful from the point of view of our defences," he said. 

How to take down a tank 

Ukraine's defence ministry has shared an infographic with instructions on how ordinary citizens can tackle Russian tanks, highlighting the weakest points that can be targeted with Molotov cocktails. 

A civilian response has formed a significant part of Ukraine's defence against Russian forces, with videos emerging claiming to show citizens in action against invading forces. 

Talks end 

A top Putin aide and head of the Russian delegation, Vladimir Medinsky, said that the first talks held between the two sides since the invasion lasted nearly five hours and that the envoys "found certain points on which common positions could be foreseen". He said they agreed to continue the discussions in the coming days. 

As the talks along the Belarusian border wrapped up, several blasts could be heard in Kyiv, and Russian troops advanced on the city of nearly 3 million. The vast convoy of armoured vehicles, tanks, artillery and support vehicles was 25km from the centre of the city, according to satellite imagery from Maxar Technologies. 

CNN reports that Maxar Technologies estimate the length of the convoy to be almost 65km long. 

Civilians make molotov cocktails in a nightclub amid Russian attacks in Kyiv, Ukraine on February 28, 2022. Photo / Getty Images 

People in Kyiv lined up for groceries after the end of a weekend curfew, standing beneath a building with a gaping hole blown in its side. 

Messages aimed at the advancing Russian soldiers popped up on billboards, bus stops and electronic traffic signs across the capital. Some used profanity to encourage Russians to leave. Others appealed to their humanity. 

"Russian soldier — Stop! Remember your family. Go home with a clean conscience," one read. 

Video from Kharkiv, Ukraine's second-biggest city, with a population of about 1.5 million, showed residential areas being shelled, with apartment buildings shaken by repeated, powerful blasts. Flashes of fire and gray plumes of smoke could be seen. 

Footage released by the government from Kharkiv depicted what appeared to be a home with water gushing from a pierced ceiling. What looked like an undetonated projectile was on the floor. 

Authorities in Kharkiv said at least seven people had been killed and dozens injured. They warned that casualties could be far higher. 

Kiwis protest, MPs meet to discuss conflict 

As MPs meet to discuss the ongoing conflict, ordinary Kiwis gathered today to protest Russia's invasion. 

A Stop the War protest organised by "the Russian and Ukrainian community of Christchurch" is under way in the southern city. 

A vocal group gathered in the city's central Cathedral Square before walking to the Bridge of Remembrance. 

Organisers say they want to show that people around the world don't want the war and that in war "information can be more powerful than bombs". 

Russian-born couple Bvalera Terentev and Lisa Terenteva protest against the war today in Christchurch. Photo / Kurt Bayer 

About 40 people gathered quietly in the square, many holding anti-war placards, Ukraine and New Zealand flags, and denouncements of Putin. 

Many Russians were in the crowd, standing shoulder to shoulder with Ukrainians. 

"Russians don't want the war," one speaker said. 

Russian-born Bvalera Terentev and Lisa Terenteva who have called Christchurch home for the past six years are appalled at the war. 

"We want to show our support not only for Ukraine but for the world against this lunatic Putin and his team who collectively are aggressive against Ukraine, the western way of understanding, democracy, freedom, intellectual development and progress," Bvalera said. 

"Putin hates that and he wants to destroy it." 

Radioactive risk 

The United Nations' nuclear watchdog says missiles have hit a radioactive waste disposal site in Kyiv, but there are no reports of damage to the buildings or indications of a release of radioactive material. 

International Atomic Energy Agency director General Rafael Grossi said on Sunday Ukrainian authorities informed his office about the overnight strike. He says his agency expects to soon receive the results of radioactivity monitoring. 

The report came a day after an electrical transformer at a similar disposal facility in the Ukrainian city of Kharkiv was damaged. 

Such facilities typically hold low-level radioactive materials such as waste from hospitals and industry, but Grossi says the two strikes highlight a "very real risk". He says if the sites are damaged there could be "potentially severe consequences for human health and the environment". 

US expels 'spies', ICC opens probe into war crimes 

The United States has said it is expelling 12 members of the Russian Mission at the United Nations, accusing them of being "intelligence operatives" engaged in espionage. 

The Biden administration's action came as pressure was heaped on Russia by the announcement of a probe into alleged war crimes committed by Russia during its invasion of Ukraine. 

The chief prosecutor of the International Criminal Court said he plans to open an investigation "as rapidly as possible" into possible war crimes and crimes against humanity in Ukraine. 

Prosecutor Karim Khan said the investigation will look at alleged crimes committed before the Russian invasion, but added that "given the expansion of the conflict in recent days, it is my intention that this investigation will also encompass any new alleged crimes falling within the jurisdiction of my office that are committed by any party to the conflict on any part of the territory of Ukraine". 

Survival of Snake Island guards confirmed 

The Ukrainian Navy has confirmed that the soldiers that confronted the Russian Navy on Snake Island survived the assault and were taken prisoner. 

On Monday, the Ukrainian Naval Forces confirmed in a Facebook post that "our brothers-in-arms are alive and well". 

They "twice bravely repulsed the attacks of the Russian occupiers" but were forced to surrender when they ran out of ammunition. 

The island, a key territorial point in the Black Sea, was "completely destroyed", the Navy said. 

A widely shared video purportedly included audio of the defenders' defiant resistance when a Russian warship demanded they surrender. 

"This is a Russian warship. I propose you lay down arms and surrender to avoid bloodshed and unnecessary victims. Otherwise, you'll be bombed," the Russians said in the clip. 

The Ukrainian defenders responded repeatedly, "Russian warship, go f*ck yourself." 

Communications with the border guards and armed forces on the island were severed after an aerial attack and artillery shelling. 

- Associated Press and agencies