President Donald Trump's planned summit with North Korean leader Kim Jong Un increasingly looks doomed.

Trump has often talked up his work on North Korea, crediting himself with creating the conditions for talks through a hardline policy, but his self-congratulatory tweets could come back to haunt him.

Trump is said to be ill-prepared for the summit and worried it could blow up in his face as an embarrassment.

South Korea may have misled Trump a bit, and North Korea is almost certainly misleading him.

North Korea experts fear that failed talks could lead the US to an even more militaristic path, possibly even to war against Kim.

President Donald Trump is less than one month away from making history as the first sitting US president to meet a sitting North Korean leader — but it's increasingly looking as if he's ill-prepared and sailing toward embarrassment.

Trump has of late talked up his work on North Korea, crediting himself with creating the conditions for talks through a hardline policy. But that self-congratulation could come back to haunt him.

North Korea has this year pursued diplomacy with its neighbors on the back of a vague promise to denuclearize. Pyongyang's apparent wish to make peace with Seoul after Trump's nuclear brinkmanship throughout last year shocked much of the world and has generated Nobel Peace Prize buzz for the president.

But now Trump worries his meeting with Kim Jong Un "could turn into a political embarrassment," The New York Times' David Sanger reported, citing administration officials.

Earlier this month, with only weeks until the historic summit, North Korea flipped on the US and South Korea, blasting them both with a series of complaints that seemed like a tantrum.

Sanger reported that Trump had questioned whether he should even go through with the summit and hastily spoke on the phone with South Korean President Moon Jae-in for reassurance.

Trump has so far stayed the course with the summit, which would represent a major part of his foreign-policy accomplishments as president. For Kim, meeting a US president is a legitimizing win, lending his country previously unattainable international credibility.

But instead of Kim hoping the US grants him that legitimacy, it now appears Trump is the one trying to hold onto a meeting that North Korea appears willing to ditch.

Additionally, Trump is reportedly not thrilled about preparing for the summit, which is expected to cover not only the issue of nuclear weapons on the Korean Peninsula but virtually every major flashpoint in East Asian geopolitics.

Time quoted a senior administration official as saying Trump "doesn't think he needs to" prepare that much for the summit with Kim.

Trump may have been misled

Trump and South Korean President Moon Jae-in meet in South Korea in November. REUTERS/Jonathan Ernst

But if Trump is ill-prepared for the summit and it does blow up in his face, he can share some of the blame.

"It increasingly looks like the Moon administration overstated North Korea's willingness to deal," said Robert Kelly, a political-science professor who's an expert on North Korea.

He added: "Moon likely exaggerated this to tie Trump to a diplomatic track to prevent him from backsliding into last year's war-threats which scared the daylights out of South Koreans. If Trump were less vain and had allowed his national security staff to vet the NK offer, he might have learned this."

It has been reported that Trump came dangerously close to striking North Korea last year. In doing so, he may have scared South Korea, not North Korea, into negotiations.

South Korea has reasons to push for diplomacy with North Korea, not least of which is that its citizens would be likely to bear the brunt of the suffering and death if war broke out.

The stuff could hit the fan

North Korea launches four missiles in this photo made from video released by North Korean state media in March. KRT via AP Video

On June 12 in Singapore, Trump is set to face a task like never before in meeting Kim.

North Korea has measurably gained from its diplomatic offensive by forging closer ties with China — and, as Trump has acknowledged, seemed to get Beijing to ease off sanctions. Trump's main achievement on North Korea thus far has been getting China to adhere to international sanctions.

Kim's unwinding Trump's win on the North Korea front with a sophisticated diplomatic ruse could prove embarrassing to Trump before the midterm elections later this year, when he'll look for a boost for the Republican Party.

North Korea experts fear that failed talks could lead the US to an even more militaristic path, possibly even to war against Kim.

Trump's newly appointed national security adviser, John Bolton, has long advocated war with North Korea — and has been partly blamed for the recent collapse in diplomatic progress.