The meeting came one day after the South Korean president arrived here on a two-day visit. He is later scheduled to hold a summit with President Donald Trump.

Pompeo and Bolton assured Moon that their country will continue to hold dialogue with North Korea, Cheong Wa Dae said in a press release.

Moon's trip here comes after Trump's second meeting with North Korean leader Kim Jong-un, held in Hanoi in late February, failed to produce any agreement, triggering a deadlock in the US-North Korea dialogue.

Seoul officials refuse to call the Hanoi meeting a failure, but Moon's hasty visit here apparently confirms a gap between the US and North Korea, which are technically at war.

Moon's two-day visit here this week is one of the briefest overseas trips he has taken so far. He is also scheduled to embark on an eight-day trip to three Central Asian countries next week, which makes his US visit more unusual.

The US is said to be against offering any rewards to Pyongyang until the communist regime fully denuclearizes, while the North has repeatedly called for the removal of international and US sanctions.

Moon has noted the need for at least a partial removal of sanctions, which he says will encourage the North to accelerate and complete its denuclearization process.

In a later meeting with US Vice President Mike Pence, Moon insisted that the Hanoi summit was only part of a process to bring about denuclearization and that restarting the US-North Korea dialogue at an early date is the key to achieving that goal.

Pence said he remains optimistic about restarting the US-North Korea talks, according to Cheong Wa Dae.

"The vice president explained that the US continues to maintain a positive stance toward US-North Korea denuclearization negotiations and that its door is always open for dialogue," Cheong Wa Dae said in a press release.

Moon and Trump were widely expected to discuss ways to restart the North Korean denuclearization talks when they meet here.

The South Korean president will head home later in the day.