A North Korea missile launch (Picture: KCNA).
The US Secretary of State Mike Pompeo says sanctions on North Korea will remain until they complete denuclearisation.
Mr Pompeo denied reports from North Korean official state media that President Donald Trump and Kim Jong-un agreed to a "step-by-step" denuclearisation process.
He said the US wants North Korea to take "major" nuclear disarmament steps within the next two years, stating "only then will there be relief from the sanctions".
Despite the "step-by-step" reports, Mr Pompeo said President Trump was clear from the start about the denuclearisation process.
However, the meeting did see a promise from Mr Kim to work towards a denuclearised Korean Peninsula and a new relationship between Pyongyang and Washington was also established.
The details are yet to have been confirmed.
After arriving in Seoul to meet US treaty allies Japan and South Korea, Mr Pompeo said the US would resume "war games" with close ally South Korea, if the North stops negotiating in good faith.
President Trump announced a halt on drills in South Korea after his meeting with Mr Kim - something that the North has wanted for a long time but is generally opposed by Seoul and Tokyo.
Following a meeting between Mr Pompeo and Japan's top diplomat, the South Korean foreign minister Kang Kyung-wha told reporters the issue of the military exercises "was not discussed in depth".
Mr Pompeo said negotiations with North Korea would restart "in the next week or so".
On Thursday, military officials from both Koreas held rare high-level talks to discuss reducing tensions across the border.
Reports suggest it is possible North Korean officials will seek a firm commitment from the South on stopping its military drills with the US.
Seoul's Defense Ministry said the talks would focus on carrying out agreements from a summit between Mr Kim and South Korean president Moon Jae-in, where they vowed to take materialised steps to reduce military tensions and eliminate the danger of war.
Mr Pompeo is expected to fly to Beijing later to update the Chinese government about the talks.