He's spent weeks cooing about the prospects of a high-level summit, set for June 12 in Singapore, with North Korea and the prospect of a huge diplomatic win -- getting that country to agree to international demands to end its nuclear program.

Asked if he deserved a Nobel Peace Prize a week ago for bringing North Korea to the table, Trump was tickled.

The specifics of a deal don't even seem to have mattered to Trump; he hasn't talked about any. But he's been bullish and excited about a meeting with the North Korea's Kim Jong Un, who he used to call "little rocket man" and once threatened with a hail of "fire and fury," but more recently, after the release of three US prisoners, called "very honorable."

With the talks he's been teasing incessantly now in doubt, the US President must be sweating his gamble on a budding relationship with a young despot.

Trump always knew the stakes were high and he's promised to be ready to fold and walk out if he didn't like what was happening at the meeting with Kim.

"If the meeting when I'm there isn't fruitful, I will respectfully leave the meeting," he told reporters on April 28

But you have to get to the meeting to walk out of the meeting. Now, Trump may have to give concessions to North Korea just to get the opportunity.

The promise of the summit in Singapore has been his favorite topic of discussion in public for some time.

"I'll be meeting with Kim Jong Un to pursue a future of peace and security for the world -- for the whole world," he told a rally of supporters in Elkhart, Indiana, earlier this month.

"And the relationship is good," Trump said, arguing that his earlier bullying of Kim had paid off. "But you remember everybody in the fake news, where they were saying, 'He's going to get us into a nuclear war.' And you know what gets you into nuclear wars? And you know what gets you into other wars? Weakness. Weakness."

But it is some combination of US demands for North Korea to end its nuclear program, military maneuvers with South Korea and the comments of his combative new national security adviser John Bolton placing North Korea on par with Libya that seem to have spooked the regime, perhaps temporarily.

And this could all work out. In vowing to withdraw the US from the Iran nuclear deal, Trump had argued he could get better deals than other presidents and the international community and he pointed to North Korea as the exemplar of his promise.

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"The United States no longer makes empty threats," Trump said about his promise to end the Iran deal and pivoting immediately to North Korea. "When I make promises, I keep them. In fact, at this very moment, Secretary Pompeo is on his way to North Korea in preparation for my upcoming meeting with Kim Jong Un. Plans are being made. Relationships are building. Hopefully, a deal will happen and, with the help of China, South Korea, and Japan, a future of great prosperity and security can be achieved for everyone."

He was offering up his own power to negotiate one nuclear deal as the reason for pulling out of one already in place. And his power as a negotiator has been the great promise on which he's rested his presidency, pulling out of international deals like the Paris climate agreement and the Trans-Pacific Partnership, promising to outdo his predecessors even though previous partners were carrying on without the US.

North Korea was to be (and may still be!) his first chance to deliver. But it clearly won't be easy. And that has been part of the allure for Trump -- doing something bigger and better.

When he welcomed home three prisoners North Korea released in advance of the talks, Trump was raising expectations for his diplomatic coup and bragging about how unexpected it would be on the world stage.

"We will see if we can do something that people did not think was going to happen for many, many years, and a lot of bad things could have happened in between," he said.