The on-again off-again summit between the U.S. and North Korea appears to be on again. A team of U.S. negotiators is in North Korea still trying to prepare for a possible June 12 summit with Kim Jong Un even after President Trump abruptly cancelled it last week. The president praised North Korea in a tweet Sunday, writing, "I truly believe North Korea has brilliant potential and will be a great economic and financial nation one day."

There are now two delegations of Americans meeting with their North Korean counterparts, reports CBS News' Ben Tracy. One set of meetings is taking place in North Korea and another delegation was dispatched to Singapore to work out logistics. It is increasingly clear that both President Trump and Kim Jong Un want the summit to happen.

Over the weekend it was Kim Jong Un and South Korean President Moon Jae-In who met for a surprise summit of their own -- their second meeting in less than 30 days. They met for two hours on the North Korean side of the demilitarized zone. North Korean state media said at the meeting Kim Jong Un "expressed his fixed will" that the summit with President Trump take place.

Briefing reporters in Seoul on Sunday, President Moon revealed that Kim also said he was still committed to the complete denuclearization of the Korean Peninsula. In the past, that offer has come with a North Korean demand that the U.S. pull out its more than 28,000 troops stationed on the peninsula and end its security commitments with South Korea and Japan.

"North Koreans could assert that we have a responsibility to denuclearize and restrict our nuclear umbrella meaning no B-1's, B-2's or B-52's flying into the Korean Peninsula -- landing in the Korean Peninsula or in operational proximity," Former Director of National Intelligence (DNI) James Clapper said on "Face The Nation" Sunday.

The North Koreans feel they've demonstrated good faith by claiming to blow up their only known nuclear test site last week. CBS News' Tracy was among a small group of journalists invited to witness the explosions.

At their meeting this weekend, South Korea's president told Kim Jong Un that if he does fully give up his nuclear weapons, the United States would offer his regime a security guarantee and "economic cooperation."