In a report in Army Times, an expert said the plan to remove troops would be "devastating" to South Korea and also other us allies. "South Korean alliance. It has nothing to do with signing peace treaties", spokesman Kim Eui-kyeom quoted Moon as saying.
Expectations have grown that North Korea would soon release the three ahead of the unprecedented summit in the coming weeks.
"A key official from the White House NSC (National Security Council) has said the report is not true at all", chief presidential press secretary Yoon Young-chan said in a statement carried by local news agency Yonhap.
In the past, Trump has questioned the need to keep more than 28,000 United States troops stationed in South Korea. But they acknowledged that a peace treaty between the two Koreas could diminish the need for the 23,500 US soldiers stationed on the peninsula. He was also concerned about the cost of maintaining the military in South Korea.
A U.S. State Department spokeswoman said she could not confirm the reports. Moon Chung-in, an adviser to the South Korean president, said negotiations with the North may change the calculus.
During the inter-Korean summit last Friday, Seoul and Pyongyang - which have been technically at war over the last 65 years as the Korean War (1950-1953) had ended with an armistice and not a definitive treaty - also pledged to sign a peace deal. The presence of US troops and their families is seen as a key deterrent that's kept more serious hostilities from breaking out on the Korean peninsula.
For Trump, withdrawing troops would have multiple benefits, said Victor Cha, a Korea scholar at Georgetown University who was, for a time, under consideration to be ambassador to Seoul.
However, is it the right time for the U.S.to consider reducing its troop presence in South Korea?
US Vice President Mike Pence is postponing his plans to travel to Brazil this month in order to ensure foreign policy resources are focused on Trump's talks with Kim, Pence's spokeswoman said.
"But from the perspective of the U.S. -South Korea alliance, it would represent a major retrenchment", Cha said.
Kim, a South Korean-born US citizen, has been held the longest.
One might think that Trump's top priority during this sensitive time would be avoiding any move that could weaken our ally's position in talks with Kim.