Tensions between North Korea and the United States had been building for years before Trump and Kim Jong Un agreed to hold what would be the first meeting between a US president and a North Korean leader.
South Korea, which brokered the talks between Washington and Pyongyang, was caught off guard by Mr. Trump's abrupt cancellation of the summit in which he cited hostility in recent North Korean comments.
Kim Chang Son, a senior official of North Korea's State Affairs Commission, arrived in Beijing on Thursday, the sources said, adding he may have planned to also visit Singapore to prepare for the recently canceled June 12 summit there. "We'd like to do it".
South Korean President Moon Jae-in and top leader of the Democratic People's Republic of Korea (DPRK) Kim Jong Un held their second summit in Panmunjom on Saturday.
National Intelligence Service Director Suh Hoon of South Korea and Kim Yong Chol, vice-chairman of the Central Committee of the Workers' Party of Korea of North Korea accompanied their leaders at the summit table.
On Saturday, President Moon Jae In and Chairman Kim Jong Un met to discuss carrying out peace agreements and resuming talks with the U.S.
Asked Friday if the North Koreans were playing games with their communications, Trump responded: "Everybody plays games".
He did not detail the nature of the new USA communication with the North.
It fanned fears in South Korea that the country may lose its voice between a rival intent on driving a wedge between Washington and Seoul.
The President later appeared to dial back on the decision, however, suggesting on Friday that the summit could still take place.
South Korea's government said in a statement released Saturday that it was relieved about the revived talks for a summit. He has erected new buildings and repainted old ones in Pyongyang, the capital, attended a concert by a South Korean girl band and let a state orchestra play American pop music.
The White House will be sending a team to Singapore in the event President Trump does meet North Korean leader Kim Jon Un.
The meeting between Trump and the North Korean Leader have been in doubt as a result of the demands for the meeting to happen.
It came as the two sides continue efforts to put a historic United States-North Korea summit back on track.
Adam Mount, a nuclear policy expert at the Federation of American Scientists, said it was a "bold but risky" move by Moon, describing the sudden summit as "a clear demonstration of how unsafe Trump's temper tantrum was". -North Korea summit a success.
Japanese Prime Minister Shinzo Abe said he respected and supported the U.S. president's move to cancel the summit while China, Pyongyang's sole major ally, urged the two foes to "show goodwill".