Washington wants to get negotiations with Pyongyang "back on track" and implement leader Kim Jong Un's "commitment" to the denuclearization of the Korean Peninsula, White House national security adviser Robert O'Brien told Axios.
O'Brien expressed cautious optimism about the fact that Kim hasn't yet delivered his promised "Christmas gift" that many expected to be a nuclear weapons test, Axios said.
Both countries have made little progress in their talks to dismantle North Korea's nuclear and missile program.
Kim said in December he will continue developing his country's nuclear deterrent and introduce a new strategic weapon in the near future, according to state-run media KCNA. His threat came after he said the U.S. did not respond to North Korea's repeated calls for concessions to reopen negotiations before the end of 2019.
The North Korean leader said in April he would wait until the end of 2019 for Washington to change its approach to denuclearization talks with Pyongyang — but it has been status quo since then and analysts warned that Kim could stay "true to his pledges."
U.S. President Donald Trump sent birthday greetings to the North Korean leader last week, but the country's foreign ministry advisor said Kim's personal feelings were insufficient to return to past diplomacy, NBC News reported.
In November, North Korea fired two short-range projectiles into the sea off its east coast.
Under Kim, the reclusive state has conducted its most powerful nuclear test, launched its first-ever intercontinental ballistic missile and threatened to send missiles to the waters near Guam.
— CNBC's Amanda Macias contributed to this report.