"Most political people would never say that, but I'm telling you under the right circumstances I would meet with him", Trump added.
It raises the tone of its warnings every spring, when Washington and Seoul carry out joint exercises it condemns as rehearsals for invasion.
The system's deployment to defend against a North Korean missile threat has become an issue in the South Korea's upcoming presidential election and with China, which is concerned that the system's long-range radar could track Chinese missile systems.
"Clearly conditions are not there right now", he added.
"Obviously he's a pretty smart cookie", said Trump, referring to North Korea's leader Kim Jong Un.
Pyongyang's latest attempted show of force was a failed missile test on Saturday that came just hours after US Secretary of State Rex Tillerson pressed the UN Security Council to do more to push the North into abandoning its weapons programme. And so that set aside, I think the president recognizes the threat that he poses, and is doing everything he can to isolate that threat, and to make sure that we bring stability to the region.
The Effect Of Trump's Tax Plan On Kentucky: It Varies
But we don't know the income levels for those brackets, so we have no idea how that would affect individual taxpayers. Here's a look at the three big stocks that could score the biggest wins from Trump's tax holiday.
"There is nothing right now facing this country and facing the region that is a bigger threat than what is happening in North Korea", the White House chief of staff said.
Earlier on Sunday, Donald Trump told CBS that he "will not be happy" if North Korea conducts another nuclear test. "And it also means being prepared for military operations, if necessary".
"Whether it's a nuclear aircraft carrier or a nuclear submarine, they will be turned into a mass of scrap metal in front of our invincible military power centred on the self-defence nuclear deterrence", the website said. China, the only major ally of North Korea and its largest trading partner, has expressed increasing concern about Pyongyang's pursuit of nuclear weapons and long-range ballistic missiles in violation of United Nations resolutions.
John McCain, who had dinner with Trump on Monday, said the President missed the point a bit.
Trump made a similar remark in an interview with Reuters the previous day, saying it would not have been easy for Kim to take over the North at a young age. "I just don't want to discuss it".
U.S. Secretary of State Rex Tillerson, who chaired the meeting, flatly rebuffed these remarks, saying the USA "will not negotiate our way back to the negotiating table with North Korea, we will not reward their violations of past resolutions, we will not reward their bad behavior with talks".