Seoul: Kim Jong Un understands that denuclearisation must happen "quickly", US Secretary of State Mike Pompeo said Thursday, warning there will be no sanctions relief for Pyongyang until the process is complete.
Washington remained committed to the "complete, verifiable and irreversible" denuclearisation of North Korea, Pompeo added, after the historic US-North Korea summit in Singapore drew criticism for its vague wording on plans for Pyongyang to give up its nuclear weapons.
"We believe that Kim Jong Un understands the urgency... that we must do this quickly," he said of the effort to have North Korea abandon its nuclear weapons.
Washington's top diplomat was in Seoul to brief his South Korean and Japanese counterparts after President Donald Trump's post-summit comments sparked confusion and concern in Tokyo and Seoul.
But Pompeo insisted at a joint press conference with the two countries' foreign ministers that there was no daylight among the allies on how to achieve the denuclearisation of North Korea.
Contrasting the Trump policy with previous US administrations, Pompeo said: "In the past, they were providing economic and financial relief before... complete denuclearisation had taken place."
"That is not going to happen, President Trump made that clear."
The UN Security Council punished North Korea over its weapons programmes with increasingly strict sanctions last year, which were also backed by China, Pyongyang's only ally.
Trump said after his meeting with Kim - the first between sitting US and North Korean leaders - that Washington would halt its joint military exercises with South Korea, an announcement that caught Seoul - and apparently the Pentagon - by surprise.
The US and South Korea conduct massive annual military exercises to maintain readiness for operations on the peninsula, a source of irritation for Pyongyang, which considers them preparations for an invasion.
South Korean Foreign Minister Kang Kyung-wha appeared to sidestep the issue at the joint press conference, saying the matter would be left to military authorities to discuss, and that the US-South Korea alliance remains "as robust as ever".
"I'm absolutely assured of our shared goal, our shared approach and how we will proceed to reach complete denuclearisation," she said.
While it is not directly involved, Japan also considers the drills vital.
The "deterrence based on them (plays) an essential role for security in northeast Asia", Japanese Foreign Minister Taro Kono said after "frank" trilateral talks Thursday.
"The US will advance the discussion on provision of security guarantees while carefully monitoring whether North Korea takes concrete steps to fullfil its commitment to denuclearisation," Kono added.
"No security guarantees have been given yet."
Pompeo said the suspension of the drills depended on productive negotiations in "good faith".
Trump had raised eyebrows Tuesday by describing his own country's drills on the Korean peninsula as "provocative", a term used by the North for the exercises.
Pyongyang describes its nuclear weapons and long-range missiles as a shield against US aggression, and has in the past linked denuclearisation to the removal of US forces from the peninsula.
North Korea observers were alarmed by the US decision on military drills, given the lack of any guarantees by North Korea at the summit.
But despite the concern among allies and analysts, the Trump administration continues to tout the summit as a success, and Pompeo said earlier that he hopes to see "major disarmament" of North Korea by 2020.
A bullish Trump declared the nuclear threat from North Korea no longer exists, and tweeted Wednesday that people "can now feel much safer than the day I took office" and can "sleep well tonight!"
The US leader also defended his decision on the military drills with South Korea: "We save a fortune by not doing war games, as long as we are negotiating in good faith - which both sides are!"
The president's latest comments are in stark contrast to his threats to unleash "fire and fury" last year in response to Pyongyang's nuclear and long-range missile tests. The North retaliated by boasting it could annihilate the United States.
After months of tensions which saw Trump and Kim trade personal insults, whirlwind diplomatic efforts were launched earlier this year, catalysed by the Winter Olympics in South Korea.
The remarkable de-escalation saw Kim reach out to Trump, conduct a historic summit with South Korean President Moon Jae-in, and visit Chinese President Xi Jinping in Beijing - his first trip abroad as leader of the North.
The reclusive regime in Pyongyang has long craved international legitimacy, and has played up the summit as a major victory for Kim, with state media calling it the "meeting of the century".