A senior administration official and a second source with knowledge say the current plan is for the second summit between President Trump and North Korean leader Kim Jong Un to be held in the Vietnamese coastal city of Da Nang.
Other ASEAN venues have also been mentioned of possibilities to be the summit venue though Singapore was the venue for the first Trump-Kim meeting in June a year ago.
During the annual Worldwide Threats hearing on Tuesday, top US Intelligence officials outlined what possible threat scenarios the US and its allies are facing in 2019, describing for senators the dangers posed by the Islamic State, North Korea, and Iran - as well as the resurgent great-power threats out of China and Russian Federation.
In late February, the two leaders are set to meet again, reportedly in Vietnam, to try to flesh out the deal.
Trump also touted what he said were his successes in Syria, where he has alarmed allies by abruptly announcing a withdrawal of U.S. troops assisting local forces against the Islamic State group, and in North Korea. "They very much want the meeting".
"This complex of sites extending beyond Yongbyon represents the totality of the North Korean plutonium-reprocessing and uranium-enrichment programs", Biegun said.
But the South Korean official ruled out the possibility of easing sanctions on North Korea or a resumption of economic projects between the two Koreas.
Pyongyang has yet to take concrete steps in that direction, in Washington's view, and the director of United States national intelligence, Mr Dan Coats, told Congress on Tuesday that it was unlikely to give up all of its nuclear weapons and has continued activity inconsistent with pledges to denuclearise.
"President Trump is ready to end this war, it is over, it is done, we are not going to invade North Korea, we are not seeking to topple the regime", Biegun told the audience during the question and answer portion of his appearance.
Earlier this week, USA intelligence agencies said they assess North Korea is unlikely to give up all of its WMD stockpiles, delivery systems, and production capabilities because its leaders view nuclear arms as critical to the regime's survival.
In Trump, he said, the United States "has a leader who, more so than any previous president, is deeply and personally committed to once and for all bringing an end to 70 years of war and hostility on the Korean peninsula". "I think most of you know where the location is".
In his tweets on Wednesday, Trump said negotiations with the Taliban to wind down the war in Afghanistan were "proceeding well". "They're doing tests and we don't want to be a position where we're behind".
"It's bigger than denuclearization, while it stands on the foundation of denuclearization, but that's the opportunity we have and those are the discussions we will be having with the North Koreans". The US President had invited the representatives of the secret service on Thursday to the Oval Office, a Meeting, the President on Twitter summed up in the following way: "Incorrect portrayals are bad for our country".
The debate is somewhat freakish, but hardly surprising: at the start of the week, the USA intelligence community presented their traditional annual reports.