By MATTHEW LEE, AP Diplomatic Writer

WASHINGTON (AP) — Secretary of State Mike Pompeo said Wednesday he was "very hopeful" that the U.S.-North Korean nuclear summit would take place as planned next month, although he laid the meeting's fate squarely on Kim Jong Un.

The decision about whether the June 12 meeting in Singapore between Kim and President Donald Trump happens is "ultimately up to Chairman Kim," Pompeo told the House Foreign Affairs Committee.

Lawmakers' questioning of Pompeo followed Trump's comment Tuesday that "there's a very substantial chance" the meeting would not proceed as scheduled.

Pompeo said the North Korean leader "asked for the meeting, the president agreed to meet with him. I'm very hopeful that meeting will take place."

The former CIA director, who has met twice with Kim since the start of April, told the committee that it's his hope that when Trump and Kim confer, "we can get the North Koreans to make this strategic shift about how best to serve the country — that the nuclear weapons program isn't in fact the thing that keeps the regime in power, but the thing that prevents the regime from being in a place it wants to be with economic success."

Pompeo said he had raised the issue of human rights with Kim "and it will be part of the discussions as we move forward." Asked by lawmakers whether he had a commitment from Kim to make it the part of a deal, Pompeo said, "We have broad outlines of what it is that each nation is prepared to do."

The summit would offer a historic chance for peace. But there also is the risk of a diplomatic failure that would allow the North to revive and advance its program.

Trump's newfound hesitation appears to reflect recent setbacks in efforts to bring about reconciliation between the two Koreas, as well as concern whether the self-proclaimed deal-maker can deliver a nuclear accord with Kim.

"The fate and the future of the Korean Peninsula hinge" on the meeting, South Korea's president, Moon Jae-in, told Trump in an Oval Office meeting Tuesday.

Trump said Kim had not met unspecified "conditions" for the summit. But Trump also said he believed Kim was "serious" about negotiations. Moon expressed "every confidence" in Trump's ability to hold the summit and bring about peace.

"I have no doubt that you will be able to ... accomplish a historic feat that no one had been able to achieve in the decades past," Moon said.

Trump said he didn't want to "totally commit" himself on whether North Korea should denuclearize all at once or in phases. "It would certainly be better if it were all in one," Trump said, before adding, "You do have some physical reasons that it may not be able to do exactly that."

Trump suggested the summit could be delayed rather than canceled: "It may not work out for June 12, but there is a good chance that we'll have the meeting."

He did not detail the conditions he had laid out for Kim but said if they aren't met, "we won't have the meeting." His spokeswoman, Sarah Huckabee Sanders, said Trump was referring to a commitment to seriously discuss denuclearization.

Skepticism about the North's intentions have mounted in recent weeks after Kim's government pulled out of planned peace talks with the South last week, objecting to long-scheduled joint military exercises between U.S. and South Korean forces. The North also threatened to abandon the planned Trump-Kim meeting over U.S. insistence on rapidly denuclearizing the peninsula, issuing a harshly worded statement that the White House dismissed as a negotiating ploy.

Trump expressed suspicion that the North's recent aggressive barbs were influenced by Kim's unannounced trip to China two weeks ago — his second in as many months. Trump said he'd noticed "a little change" in Kim's attitude after the trip.

The president said he hoped Chinese President Xi Jinping was actually committed to the goal of denuclearizing the Korean Peninsula, calling him a "world-class poker player." Trump said he was displeased by China's softening of border enforcement measures against North Korea.

Trump encouraged Kim to focus on the opportunities offered by the meeting and to make a deal to abandon his nuclear program, pledging not only to guarantee Kim's personal security but also predicting an economic revitalization for the North.

"I will guarantee his safety, yes," Trump said, noting that promise was conditioned on an agreement to complete, verifiable and irreversible denuclearization. Trump said if such an agreement is reached, China, Japan and South Korea would invest large sums to "make North Korea great."