WASHINGTON (Reuters) - U.S. Secretary of State Mike Pompeo said on Monday he would likely travel back to North Korea “before too terribly long” to try to flesh out commitments made at a landmark summit between President Donald Trump and North Korean leader Kim Jong Un in Singapore last week.

FILE PHOTO: U.S. Secretary of State Mike Pompeo attends the daily briefing at the White House in Washington, DC, U.S., June 7, 2018. REUTERS/Carlos Barria/File Photo

Pompeo, who has traveled twice to North Korea this year and met Kim for a third time at the June 12 Singapore summit, told an audience in Detroit that Kim had made “very clear his commitment to fully denuclearize his country,” but there was a great deal of work to do.

When asked after delivering a speech to the Detroit Economic Club if there would need to be a second summit involving Kim and Trump, Pompeo said it was “hard to know.”

“There is a lot of work between here and there. My team is already doing it. I’ll likely travel back before too terribly long,” he said. “We still have to flesh out all the things that underlay the commitments that were made that day in Singapore.”

On his part, Pompeo said, Trump had committed in Singapore to alter the existing armistice agreement that halted the 1950-53 Korean War and to providing security assurances Kim needed.

“And if we can get those two done in a way that matches, we will have reduced a global threat that has bedeviled the United States and the world for decades,” Pompeo said.

At the Singapore summit, the first meeting between a serving U.S. president and a North Korean leader, Kim reaffirmed a commitment to “work toward complete denuclearization of the Korean peninsula”, while Trump said he would end “provocative” joint U.S.-South Korean military exercises.

A U.S. official said on Monday the United States and South Korea had agreed to suspend a joint military exercise scheduled to take place in August code-named “Ulchi Freedom Guardian,” in line with Trump’s comments. The official said an official announcement was expected in the coming days.

Pompeo told reporters on a visit to Seoul last Wednesday he would take the lead role in driving the North Korea negotiation process forward and that he anticipated that the two sides would resume engagement “some time in the next week or so.”

He said Washington hoped to achieve “major disarmament” by North Korea within the next 2-1/2 years, within Trump’s current presidential term, which ends on Jan. 20, 2021.

On a visit to Beijing last week, Pompeo said tough sanctions would remain on North Korea until its complete denuclearization, apparently contradicting the North’s view that the process agreed at the summit would be phased and reciprocal.

Earlier on Monday, South Korea’s First Vice Foreign Minister Lim Sung-nam told Washington’s Center for Strategic and International Studies think tank that sanctions relief would only be possible once there was “substantial progress” in denuclearization.

The United States had led an international sanctions drive to press North Korea to abandon development of nuclear weapons capable of reaching the United States.

Although Trump has hailed the Singapore summit as a success, skeptics have questioned whether he achieved anything new, given that Pyongyang, which has rejected unilateral nuclear disarmament, appeared to make no new concrete commitments.