Washington (CNN) A US delegation arrived in North Korea on Sunday for preparatory talks ahead of a potential meeting between President Donald Trump and North Korean leader Kim Jong Un, Trump said on Sunday.

"Our United States team has arrived in North Korea to make arrangements for the Summit between Kim Jong Un and myself," Trump tweeted. "I truly believe North Korea has brilliant potential and will be a great economic and financial Nation one day. Kim Jong Un agrees with me on this. It will happen!"

Our United States team has arrived in North Korea to make arrangements for the Summit between Kim Jong Un and myself. I truly believe North Korea has brilliant potential and will be a great economic and financial Nation one day. Kim Jong Un agrees with me on this. It will happen! — Donald J. Trump (@realDonaldTrump) May 27, 2018

Three senior US officials with knowledge of the situation told CNN details about the preparatory talks. The group included US Ambassador to the Philippines, Sung Kim, and is a clear sign the summit between the two leaders is back on track. Kim is meeting with Choe Son Hui, an experienced North Korean diplomat who specializes in the country's relationship with Washington.

The Washington Post previously reported on the team entering into North Korea.

A team of US officials focused on the logistics of a summit left this weekend for Singapore. The delegation that entered North Korea on Sunday is more focused on the substance of the talks.

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