Just a few months ago, U.S. President Donald Trump and North Korea's young dictator, Kim Jong Un, were trading insults and threatening nuclear war. Journalists in attendance reported that the North Korean leader appeared "stunned" by the remarks - although he reportedly smiled after sitting down.
However, such a move would also require the authorisation of South Korea, as well as North Korean ally China.
It wasn't immediately clear what specific progress, if any, had been made in preliminary discussions between US and North Korean officials in the run-up to the Tuesday summit.
"He won't have that opportunity again", the US president added.
"We are hopeful this summit will have set the conditions for future successful talks", Pompeo said on Monday evening.
"I feel really great", Trump said as he sat with Kim. Though CNN reports the almost five-hour talk ended with only a "vague pledge" that North Korea will disarm, many on Twitter were more taken with what the world leaders dined on during their important discussion. After the signing, aides for both men applauded.
Among those joining the leaders on the USA side were Secretary of State Mike Pompeo, White House chief of staff John Kelly and national security adviser John Bolton. "So it's a great honor", President Trump said at the signing ceremony early Tuesday morning.
The last-minute change of schedule came as both sides finalized preparations for the meeting.
But the apparent showing off was brought to an abrupt halt moments later when the same aide quickly shut the door of the Beast and ushered Trump as well as Kim away from the presidential vehicle.