South Korean President Moon Jae-in, after meeting Saturday with the regime leader, told reporters Sunday "that Chairman Kim and I have agreed that the June 12 summit should be held successfully, and that our quest for the Korean peninsula's denuclearisation and a perpetual peace regime should not be halted."
Trump said arrangements are "moving along very nicely," including sessions Sunday in North Korea. Trump made the comments Saturday night about the summit from the Oval Office as he welcomed Josh Holt, an American prisoner released by Venezuela.
"A lot of people are working on it," Trump said. "It's moving along very nicely. We're looking at June 12 in Singapore. That hasn't changed. And it's moving along pretty well, so we'll see what happens."
On Sunday, a U.S. advance team departed Japan and arrived at Tongilgak in North Korea -- north of the demilitarized zoned -- for planning meetings that are expected to continue Monday and Tuesday, Heather Nauert, a State Department spokesman, told The Washington Post.
Trump said preparation meetings are going on "as we speak in a certain location which I won't name, like the location, it's not very far from here."
On Thursday, Trump sent a letter to Kim calling off the event. "Please let this letter serve to represent that the Singapore summit, for the good of both parties, but to the detriment of the world, will not take place," Trump wrote in the letter. "You talk about your nuclear capabilities, but ours are so massive and powerful that I pray to God they will never have to be used."
He noted "tremendous anger and open hostility displayed in your most recent statement," apparently referring to comments from officials like Choe Son Hui, who slammed Vice President Mike Pence for comments on Libya and North Korea.
But Trump has since toned down his remarks.
During the Oval Office meeting that including the media, Trump said: "I think there's a lot of goodwill. I think people want to see if we can get the meeting and get something done. If we got that done, and if we can be successful in the denuclearization of the Korean Peninsula, it would be a great thing for North Korea, it would be a great thing for South Korea. It would be great for Japan and great for the world; great for the United States, great for China."
Trump said "I'd rather not say" whether he has spoken with North Korea's leader.
On Saturday, Kim met on the North side of the demilitarized zone with South Korean President Moon Jae-in. Their last meeting on April 27 was on the South side.
"What is unclear to Chairman Kim Jong Un is not the will for denuclearization, but the concern that if [North Korea] denuclearizes, whether the U.S. can end hostile relations and guarantee the security of the [Kim] regime," Moon said Sunday to reporters.
Moon also said South Korea favors removing nuclear weapons from the region.
"Our journey to the complete denuclearization of the Korean Peninsula and a permanent peace agreement cannot be stopped, and we have decided to cooperate closely," Moon said.
In a statement Sunday, North Korean state media said the meeting took place "all of a sudden."