North Korea test-fired missiles days after a visit to the region by top defence and diplomatic leaders, the White House said on Tuesday, in Pyongyang's first overt challenge to the administration of US President Joe Biden.
But administration officials, speaking anonymously, downplayed the missiles as "common" military testing and said they would not block Washington's efforts to engage with North Korea on denuclearization.
Two missiles were fired on Sunday, they confirmed, echoing Pyongyang's past practices for provoking and testing both Washington and Seoul.
“We’ve learned nothing much has changed,” Mr Biden said about North Korea in a brief exchange with reporters in Columbus, Ohio.
They were short-range, non-ballistic missile systems that do not fall under UN security council resolutions banning more threatening weapons, a senior US administration official told reporters.
It was nothing like the nuclear weapon tests or ballistic missile launches that Pyongyang has used to provoke previous US governments, the official said.
"What we saw this weekend does not fall in that category," the official said.
"It is common practice for North Korea to test various systems," the official added. "We do not respond to every kind of test."
Analysts took them as a modest challenge to the new administration as it tries to engage with North Korean leader Kim Jong-un in talks on ridding the peninsular of nuclear weapons.
The launches came days after US Secretary of State Antony Blinken and Defence Secretary Lloyd Austin visited Japan and South Korea to discuss their alliance and security issues in the region, with nuclear-armed North Korea regarded as a central threat.
They also followed joint exercises by US and South Korea defence forces between March 8 and 17.
While Mr Blinken and Mr Austin were in Seoul on March 18, North Korea's first vice foreign minister Choe Son-hui accused the US of a "lunatic theory of a 'threat from North Korea' and groundless rhetoric about 'complete denuclearisation'".
Mr Biden's two-month-old administration hopes to reignite negotiations with the Kim Jong Un regime on its nuclear arsenal after efforts by the previous administration of Donald Trump stalled.
Initial outreach from Washington to Pyongyang has turned up empty, but US officials are hopeful they can reconnect, while working in coordination with allies Japan and South Korea.
Biden officials are now finalizing a strategy to restart talks that the White House will discuss with Japanese and South Korean security officials next week, the administration official said.
"We have taken efforts and we will continue to take efforts" to communicate, the official said.
Such launches, especially of nuclear-capable ballistic missiles, are commonly accompanied by boastful announcements from Pyongyang and strident attacks from Seoul.
North Korea expert Martyn Williams of the Stimson Centre called the silence "curious".
"North Korea usually announces such tests after the fact through state media but nothing this time," Mr Williams wrote on Twitter.
"The tests are usually also reported pretty quickly after they happen through Japanese and Korean media, but nothing."
Another North Korea expert, Jeffrey Lewis, said that the tests might have been of short-range coastal defence cruise missiles.
"If that's what this is, it's a pretty mild response to a US-ROK military drill," he said, referring to South Korea.
