"North Korea has a familiar menu of provocations when it wants to send a message to the USA administration - ballistic missiles of various range, mobile and submarine launch platforms, nuclear and thermonuclear tests - experts have rightly recognized what took place last weekend as falling on the low end of that spectrum", he added.
North Korea maintained and developed its nuclear and ballistic missile programs throughout 2020 in violation of worldwide sanctions, helping fund them with some $US300 million ($A393 million) stolen through cyber hacks, according to independent United Nations sanctions monitors.
'"We do not see the activity that took place this weekend as closing that door", a senior official said Tuesday, referring to future attempts at diplomacy.
"We've learned nothing much has changed", Biden told reporters before boarding Air Force One en route to Washington from Columbus, Ohio, where he was making a visit to promote the American Rescue Plan. Neither Obama nor Trump administrations were able to stop North Korea from advancing its weapons systems.
Top U.S. and Chinese officials traded sharp and unusually public barbs in Alaska last week in their first face-to-face meetings since President Joe Biden took office, where Secretary of State Antony Blinken said Washington is united with its allies in pushing back against Chinese authoritarianism.
A top U.S. general last week had warned of the near-term possibility of a far more provocative move: a decision by North Korea to begin flight testing an improved design for its inter-continental ballistic missiles. The Trump White House said it would not ease sanctions until North Korea had taken significant steps toward denuclearization.
"North Korea has a familiar menu of provocations when it wants to send a message to a USA administration", said the official, who listed ballistic missiles fired from mobile launchers and submarines, as well as nuclear and thermonuclear tests as falling into that category.
CNN reported last week that US intelligence assessed North Korea could be preparing to carry out their first weapons test since Mr Biden was sworn-in as president and that US officials were on alert as US Secretary of State Tony Blinken and Defence Secretary Lloyd Austin traveled to Asia for meetings with their Japanese and South Korean counterparts.
Initial outreach from Washington to Pyongyang has turned up empty, but USA officials are hopeful they can reconnect, while working in coordination with allies Japan and South Korea.
Relations between the USA and North Korea, once hailed as potentially promising after former President Donald Trump's three meetings with North Korean leader Kim Jong Un, have been tense with no substantive contact for more than a year. -South Korean military exercises and issued a warning to the Biden administration over the drills.
The administration has not gotten a direct response from North Korea, but in a statement carried by state media last week, Choe Son Hui, the first foreign minister, rejected talks until the United States "rolls back its hostile policy" toward Pyongyang. "According to the Defense Department, it's business as usual, there's no new wrinkle in what they did", Biden said.
Since Mr Trump's first meeting with Mr Kim in Singapore in 2018, the North has not conducted nuclear or long-range missile tests, although analysts believe they have pressed ahead with their programs on both.
"It is a normal part of the kind of testing that North Korea would do", the official said.
"We are under no illusions about the difficulty this task presents to us", the official said. It's defied expectations of Republican and Democratic administrations alike. We've tried it at the highest levels of the head of state. -China relations are heading into a complex period.
Those targeted by the European Union sanctions are North Korea's State Security Minister Jong Kyong Thaek, Public Security Minister Ri Yong Gil and the Central Public Prosecutor's Office.