WHITE HOUSE - U.S. President Donald Trump said Wednesday that the date and location of his summit with North Korean leader Kim Jong Un would be announced within three days, but that the meeting would not occur at the Korean Demilitarized Zone, which he had previously suggested was a possible venue.
Trump made the remarks to reporters at the White House, shortly after North Korea freed three American detainees.
The Korean-Americans are heading home with Secretary of State Mike Pompeo, who met with Kim for 90 minutes — the second such meeting in little more than a month.
Trump said he and Vice President Mike Pence would go to Joint Base Andrews, Maryland, to greet the freed Americans when they arrive at 2 a.m. (EDT) Thursday.
"It'll be quite a scene," predicted Trump, saying their return was "very exciting" because "it represents something very important to this country. People never thought a thing like this could happen."
WATCH: Trump on being at airport to greet freed hostages
?Trump termed current U.S. communication with Pyongyang as "serious and positive" and expressed his appreciation to Kim for releasing the Americans to Pompeo.
By late Wednesday, several media outlets reported that Singapore would be the likely summit site.
Asked whether the unprecedented summit between an American president and a North Korean leader might be scuttled, Trump replied that "everything can be scuttled."
Trump has said the goal is for North Korea to agree to denuclearize. On Wednesday, he said, "We have a chance that something really great for the world and great for North Korea" could be achieved.
A senior U.S. official present for the exchange of detainees in Pyongyang told journalists traveling with Pompeo that a North Korean official informed the secretary of state that Kim had granted amnesties to the three Americans.
The released men were brought to the secretary's aircraft and were "able to walk on the plane without assistance," according to a White House statement.
The detainees were on their way to the United States after stopping at Yokota Air Base in Japan. From that point forward, they were traveling in a separate plane from Pompeo.
Tony Kim and Kim Hak Song were teaching at the Pyongyang University of Science and Technology when they were separately detained in 2017, accused of participating in anti-state activities and trying to overthrow the government.
The third detainee, Kim Dong Chul, was arrested in Rason on the northeast tip of North Korea in October 2015 and sentenced to 10 years in prison with hard labor the following year after being convicted of espionage.
A U.S. official who participated in the latest talks in Pyongyang said substantial progress was made in planning for the summit, and "we also agreed to meet again in person to finalize the details."
Pompeo told reporters traveling with him that holding such a summit would have been more difficult had the Americans still been detained.
"For decades, we have been adversaries," Pompeo said of the North Koreans. "Now we are hopeful that we can work together to resolve this conflict, take away threats to the world and make your country have all the opportunities your people so richly deserve."
Pence said in a statement that while the Trump administration "is encouraged that North Korea freed these innocent hostages, we will not let off the pressure until we achieve full denuclearization."
?White House press secretary Sarah Sanders told reporters on Wednesday afternoon that "the maximum pressure campaign has worked," adding that in addition to the president's efforts "some of that success is due to our allies and partners," especially the leaders of China, Japan and South Korea.?
Some members of Congress, while applauding the release of the three Americans, are expressing concern about the Trump-Kim summit.
"Releasing detainees is the easy part; the difficult part will be reaching an agreement with the North Koreans that establishes a strong verification regime that can ensure genuine denuclearization," said a statement from House Democratic Whip Steny Hoyer of Maryland.
"Congress has yet to see a concrete strategy from the president as to how he intends to avoid giving Mr. Kim a propaganda victory without securing the kind of verifiable commitment on denuclearization necessary for any summit to be a success," Hoyer said.
Republican Senator Bob Corker of Tennessee said he was thankful for the release of the Americans who were unjustly detained.
"We must approach North Korea's recent overtures and the potential for talks over denuclearization with great caution, and I believe the administration fully understands that and is preparing in the appropriate way," the Foreign Relations Committee chairman said in a statement. "The committee will conduct appropriate oversight as the discussions with North Korea continue."
The removal of tens of thousands of U.S. military personnel from the Korean Peninsula will not be on the table for the Trump-Kim talks, according to Defense Secretary Jim Mattis.
Testifying before the Senate Appropriations Committee on Wednesday, the defense secretary described the U.S. forces in South Korea as a stabilizing presence for the entire region.
"And this I would just say resonates among allies, and not just in Japan and Korea, because those forces are in the Northwest Pacific, but also around the world when they see that when trouble looms, we don't walk away," said Mattis.
Nike Ching at the State Department contributed to this report.