North Korea's recent round of missile tests has stoked tensions between the hermit kingdom and the South, with Kim Jong-un's sister warning Seoul ministers against "reckless" comments.

The North fired what was believed to be an intercontinental ballistic missile (ICBM) towards the East Sea on March 24, South Korea's military said last month.

South Korea's President Moon Jae-in said the recent launch was a "breach of the suspension of intercontinental ballistic missile launches promised by Chairman Kim Jong-un to the international community".

"It poses a serious threat to the Korean peninsula, the region and the international community," he said, adding that it was a "clear violation" of UN Security Council resolutions.

South Korean Defence Minister Suh Woo responded with particularly strong comments in relation to the tests at a military event on Friday local time.

"(Our troops) are capable and ready to accurately strike the origin of North Korea's missile firing and the command and support facilities in a clear case of missile firing," he said.

Kim Yo-Jong, sister of North Korea's leader Kim Jong-un. Photo / AP

The North immediately turned it back around on Seoul, accusing their democratic neighbour of provoking confrontation, with high-ranking officials declaring the South was on a "hysterical pursuit" for further conflict.

Kim Yo-Jong, who is often referred to as the nation's "de facto second-in-command", warned South Korea should "discipline itself if it wants to stave off disaster".

"(Suh) is a confrontation maniac," Kim in a statement released to North Korean state-run media.

"His reckless and intemperate rhetoric about the 'pre-emptive strike' has further worsened the inter-Korean relations and the military tension on the Korean Peninsula,'" Kim said. "Now we cannot but take his confrontation hysteria seriously and reconsider many things."

"The senseless and scum-like guy dare mention a pre-emptive strike at a nuclear weapons state. South Korea may face a serious threat owing to the reckless remarks made by its defence Minister ... South Korea should discipline itself if it wants to stave off disaster."

Pak Jong Chon, secretary of North Korea's ruling Workers' Party's central committee, also fired off at Suh in an extraordinary warning over the weekend.

He warned the South that "any slight misjudgment and ill statement rattling the other party under the present situation" could lead to "a dangerous conflict and a full-blown war".

Pak insisted he was forced to issue an immediate statement to have the North Korean "people and army to get to know about the South Korean military's hysteric pursuit for confrontation".

"Any slight misjudgment and ill statement rattling the other party under the present situation where acute military tension persists may become a spark triggering off a dangerous conflict and a full-blown war," he said.

Protesters stage a rally denouncing North Korea's missile launch near the US Embassy in Seoul, South Korea. Photo / AP

Pak said North Korea would "mercilessly direct military force into destroying major targets in Seoul and the South Korean army" if South Korea were to launch a pre-emptive attack.

The escalation has been met with criticism abroad, with Japan officially condemning the North for launching the suspected intercontinental ballistic missile in March which landed in his country's exclusive economic zone

Japan's Prime Minister Fumio Kishida described it as an "outrageous and unforgivable" act, declaring the rogue nation's military was threatening "the peace and safety of Japan, the region and the international community".

North Korea claimed to have successfully test-fired a Hwasong-17 missile - a long-range ICBM that analysts say may be capable of carrying multiple warheads - which it first unveiled at a military parade in 2020.

However, South Korean analysts remained sceptical of the details.

"US and South Korean intelligence has determined that what was fired on March 24 was a Hwasong-15," the defence ministry official told AFP.

Seoul and Tokyo had separately confirmed at the time that the March 24 missile had flown higher and longer than any previous test - but analysts later pointed to discrepancies in North Korea's account.

According to Seoul-based specialist website NK News, debris from the failed test fell in or near Pyongyang as a red-tinged ball of smoke zigzagged across the sky.

North Korea's state media - Rodong Sinmun and KCNA news agency - did not report on the failed launch at the time.

The March 24 launch was trumpeted by state media, with KCTV releasing a slick video purportedly showing the giant missile being successfully test-fired.

The US condemned North Korea and urged the world to hold Pyongyang responsible for violating UN Security Council resolutions.

Washington "strongly condemns the Democratic People's Republic of Korea for its test of a long-range ballistic missile", White House spokeswoman Jen Psaki said in a statement.

"This launch is a brazen violation of multiple UN Security Council resolutions and needlessly raises tensions and risks destabilising the security situation in the region."