US President Donald Trump announced on Tuesday that his much anticipated summit with North Korean leader Kim Jong Un may be delayed. He made his remarks while receiving at the White House South Korean President Moon Jae In. "It may not work out for June 12," Trump said of the Singapore meeting, adding in a now familiar non-committal riff: "if it does not happen, maybe it will happen later." "There are certain conditions we want to happen. I think well get those conditions. And if we dont, we wont have the meeting," he said. Politically, Trump has invested heavily in the success of the meeting, so most US officials, as well as outside observers, privately expect it will go ahead. But as the date draws near, Trumps divergence from his top aides, the differences between the two sides and the astronomically high stakes are coming into sharp relief. Success could lead to peace on the Korean peninsula and end the threat of a nuclear conflagration. Failure could all but destroy hopes of a peaceful solution to the crisis. "You never know about deals," Trump said. "Ive made a lot of deals. You never really know." Trump expressed suspicion that the Norths recent aggressive barbs were influenced by Kims unannounced trip to China two weeks ago — his second in as many months. Trump said he noticed "a little change" in Kims attitude after the trip. "I dont like that," he said. The president added that 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 Chinas softening of border enforcement measures against North Korea. North Koreas willingness to denuclearize -- the very basis for the talks -- was recently plunged into doubt when the government denounced US demands for "unilateral nuclear abandonment." Pyongyang also canceled at the last minute a high-level meeting with the South in protest over joint military drills between Seoul and Washington. Despite the Norths move, Trump said he believes Kim is willing to give up nukes. "I do think he is serious. I think he is absolutely very serious," the US president said. 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 Kims 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." Moons trip to the White House represented an effort to salvage the rare diplomatic opening. The dovish Moon deployed a tactic frequently used by foreign leaders who meet this most mercurial of presidents: flattery. "Thanks to your vision of achieving peace through strength as well as your strong leadership," Moon said in the Oval Office, "we find ourselves standing one step closer to the dream of achieving denuclearization on the Korean peninsula." "All this was possible because of you, Mr. President," Moon added, taking pains to stress the concrete results of diplomacy so far -- most notably the release of three US prisoners from North Korean jail. "The fate and the future of the Korean Peninsula hinge" on the meeting, Moon added "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.” South Korea -- deeply worried about Kims bellicose weapons testing and Trumps similarly aggressive warnings about "fire and fury" -- was instrumental in convincing the two Cold War foes to sit down and talk. Moon sent his own national security advisor to the White House in March, carrying an offer of talks and word that North Korea may be willing to abandon nuclear weapons, an enticing prospect.