The 1994 deal included detailed commitments from North Korea to close plutonium-producing nuclear reactors and secure spent fuel rods, so they couldn't be turned into weapons grade fuel.
Moon Seong Mook, a former South Korean military official, said Trump's comments on the drills confirmed what many in South Korea had feared all along - that North Korea would attempt to drive a wedge between Washington and Seoul and gain substantial concessions from an unconventional US president who thinks much less of the traditional alliance than his predecessors. The omission of the words "verifiable" and "irreversible" from the phrasing on denuclearization suggested North Korean resistance to Trump's requests.
The South Korean government also appeared caught off guard.
Admittedly, Trump said Kim was very pleased with the development. "So we are maybe going back to the six-party format", he said.
"My first question is whether our allies, the South Koreans, were consulted in advance of suspending these military exercises", Reiss told Reuters. "I think the summit talk is very important because we are really covering a lot of people".
Second, Trump came out with this decision about the war games after the summit all on his own.
The Chinese position echoes comments made by Russian Foreign Minister Sergey Lavrov, who called for a lifting of sanctions during a May visit to Pyongyang, North Korea's capital.
Trump called Kim a worthy negotiator and plans to invite him to the White House in the near future. A federal investigation into alleged Russian meddling in the 2016 election also hangs over his presidency.
The withdrawl of support for LGBTQ rights is one of the ripple of consequences from the Trump-Kim summit.
"These are negotiations so the Secretary has been in full consultation with Secretary of State Pompeo, as well as the president", said White.
Trump himself scoffed at the sceptics earlier on Tuesday. "I hope it will be eventually".
He added, "While Mr. Trump provides the background, I want [the government] to win a firm commitment from North Korea that a Japan-North Korea summit meeting will be held".
"Apparently jet-fuel is so expensive, it's worth casting aside a 60-year ally and friend", Robert Kelly, a professor at South Korea's Pusan National University, said.
The statement seemed to surprise South Korean President Moon Jae-in. There is no doubt that this is a historic moment in the relationship between the countries and the region.
Trump is scheduled for a news conference at 4pm local time.
Although the Pentagon said Defense Secretary Jim Mattis was consulted ahead of time, current and former USA defense officials expressed concern at the possibility that the United States would unilaterally halt military exercises without an explicit concession from North Korea lowering the threat from Pyongyang. The agreement sought an end to North Korea's fledgling nuclear program with a goal of complete denuclearization, just as in Trump's deal. "Why not ease sanctions?"
One of President Donald Trump's more controversial pledges at his meeting with North Korean leader Kim Jong Un - that the United States would halt joint military exercises on the Korean Peninsula - touched off confusion on Capitol Hill as an influential GOP senator asserted the exercises would nonetheless continue.