SEOUL - The United States hopes to achieve "major disarmament" by North Korea within the next 2-1/2 years, U.S. Secretary of State Mike Pompeo said on Wednesday, seeking to give assurances after a summit this week that Pyongyang will eventually give up its nuclear weapons.

President Donald Trump met North Korean leader Kim Jong Un in Singapore on Tuesday, issuing a joint statement afterward that reaffirmed the North's commitment to "work toward complete denuclearization of the Korean Peninsula" and gave U.S. guarantees of security to North Korea.

But the brief document from the two leaders' historic meeting provided no details on when Pyongyang would give up a nuclear weapons program that has advanced enough to threaten the United States, or how the dismantling might be verified.

Pompeo was in Seoul on Wednesday to brief South Korean officials on the summit. Speaking to a small group of reporters and asked if he would like to accomplish major nuclear disarmamentwithin Trump’s current term, which ends on Jan. 20, 2021, Pompeo replied:

"Oh yes, most definitively. Absolutely ... you used the term major, major disarmament, something like that? We're hopeful that we can achieve that in the 2-1/2 years."

"I am ... confident they understand that there will be in-depth verification," Pompeo said. He added that the initial agreement between Trump and Kim had not captured all of what had been agreed by the two sides.

"Not all of that work appeared in the final document. But lots of other places where there were understandings reached, we couldn't reduce them to writing, so that means there’s still some work to do, but there was a great deal of work done that is beyond what was seen in the final document that will be the place that we will begin when we return to our conversations," Pompeo said.

Critics in the United States said the joint statement by the two leaders was short on detail and that Trump had made too many concessions to Kim, whose country is under U.N. sanctions for its nuclear and weapons programs and is widely condemned for human rights abuses.

'MUCH SAFER'

Trump, who returned to Washington early on Wednesday, hailed the meeting with Kim, the first between a sitting U.S. president and a North Korean leader, as a success that had removed the North Korean nuclear threat.

"Everybody can now feel much safer than the day I took office," Trump said on Twitter.

"There is no longer a nuclear threat from North Korea. Meeting with Kim Jong Un was an interesting and very positive experience. North Korea has great potential for the future!"

Pompeo is charged by Trump with leading the follow-on negotiations with North Korea.

"I don’t know exactly what the timing will be for our next conversation with the North Koreans,"Pompeo said. "I would anticipate it will be fairly quickly after we return to our home countries."

"I don’t know exactly what form that will take, but I'm very confident that by some time in the next week or so we will begin the engagement."

North Korea's state media also hailed the summit as a success, including highlighting Trump's surprise announcement after the summit that the United States would stop military exercises with South Korea.

(Writing by Arshad Mohammed and Alistair Bell; Editing by Frances Kerry)

© Reuters News 2018