Prime Minister Jacinda Ardern says the sanctions New Zealand has put on Russia are working, and it's important for Aotearoa to play its part. 

It comes after Foreign Minister Nanaia Mahuta and Trade and Export Growth Minister Damien O'Connor announced on Wednesday the Government will apply 35 per cent tariffs to all imports from Russia. 

In a press conference on Thursday, Ardern said the Government had stayed in regular contact with Ukraine about what the needs are. 

She said economic sanctions were a priority and the Government had moved on that, and was also considering on a rolling basis other requests for assistance. 

Ardern was also asked about the Greens call for a rent freeze and said the priority was ensuring there was enough supply because that was a big driver of rent prices. She said more house building had contributed to rental stability prices in Auckland. 

She added the Government has already changed tenancy laws and restricted when landlords could increase rentals, and brought in measures to make renting easier for tenants such as the healthy home standards. 

"In looking at some of these options in the past, one of the concerns is it could stifle supply and that would make things worse," she said of rent freezes. 

The Prime Minister spoke to media today from Auckland as she visits businesses ahead of re-starting her international travel agenda. 

She spoke soon after director general of health Dr Ashley Bloomfield and director general of Public Health Dr Caroline McElnay started the day's Covid-19 press conference in Wellington. 

That will be McElnay's final press conference: her last day at the Ministry of Health is tomorrow. 

Yesterday Bloomfield also announced he was resigning and will leave at the end of July, a year before his term was due to end. 

Public Health deputy director Dr Niki Stefanogiannis is also leaving on Friday – she and McElnay leave a big hole at the top of the Public Health unit. One of the factors in the departures is believed to be burnout after dealing with Covid-19. 

In his press conference yesterday, Bloomfield referred to the gendered nature of the negative criticism faced by the women helping lead the Covid-19 response compared to the criticism he had faced, saying it needed to be addressed. 

Concerns are also rising about the number of Covid-19 cases that are being missed by rapid antigen tests, as the Omicron outbreak continues. 

Ardern could also be questioned about the Government proposal to ban soft drinks and other sugary drinks in schools after Education Minister Chris Hipkins put out a consultation paper on it today. 

Ardern will speak while visiting businesses in Auckland as she prepares for her first international travel in more than two years. 

Her first trip will be in the Asia region, and Ardern will take a business delegation, followed by export and trade-related trips to Europe and North America. 

New Zealand is still in negotiations for a free trade agreement with the European Union. 

Meanwhile, the upgraded free trade agreement with China came into effect today. Trade Minister Damien O'Connor said China had continued to be an important market during Covid-19, with goods and services exports reaching $21.5 billion in 2021. 

He said the UK free trade agreement would also add up to $1 billion to New Zealand's GDP.