WASHINGTON (BLOOMBERG) - The commander of US forces in South Korea cited a "palpable" decline in tensions amid US-North Korean peace talks, but cautioned there's little evidence that Mr Kim Jong Un is willing to give up his nuclear arsenal.

"Today is Day 440 since the last strategic provocation" by North Korea through a missile or nuclear test, Army General Robert Abrams told the Senate Armed Services Committee on Tuesday (Feb 12).

That's meant "a marked reduction in tensions" on the Korean Peninsula, he said, and a reduced risk of miscalculation.

While Gen Abrams credited President Donald Trump's talks with Mr Kim, which will resume in a second summit meeting in Hanoi on Feb 27-28, as contributing to the improved atmosphere, he offered little optimism that Mr Trump's efforts will lead to his goal of a nuclear-free North Korea.

"I remain clear-eyed," Gen Abrams said, adding that "little to no verifiable change has occurred in North Korea's military capabilities".

In a written statement to the committee, Admiral Philip Davidson, commander of the US Indo-Pacific Command, was even more direct, echoing a finding by US intelligence agencies last month that Mr Kim views his nuclear weapons as indispensable to maintaining his autocratic power.

"We think it is unlikely that North Korea will give up all of its nuclear weapons or production capabilities, but (Mr Kim) seeks to negotiate partial denuclearisation in exchange for US and international concessions," he said.

Meanwhile, the US's top envoy to talks with North Korea gave a cautious view on the upcoming Trump-Kim summit during a closed-door briefing with South Korean lawmakers visiting Washington, the Yonhap News Agency and other South Korean media reported.

Special Representative for North Korea Stephen Biegun told a delegation led by National Assembly Speaker Moon Hee-sang on Monday that there might not be enough time to resolve all issues in the two weeks before the summit, Yonhap said, without disclosing how it got the information.

He said there was a chance the two sides could agree on a denuclearisation timeline, according to Yonhap.

Mr Biegun said that the two parties planned to draft a joint statement and narrow down their differences during the next round of working-level negotiations, the DongA Ilbo newspaper reported. The US Embassy in Seoul said it was unable to confirm Mr Biegun's comments.

At the Senate hearing, Senator Tim Kaine, a Virginia Democrat, said "we have to be sceptical" unless North Korea offers a full inventory of its nuclear capabilities.

That's a demand the Trump administration has put off for later in its back-and-forth with Pyongyang.