U.S. President Donald Trump tweeted on Sunday that his schedule for the day would include a speech to U.S. troops and a "long planned" visit to the Demilitarized Zone (DMZ) on the border between the Republic of Korea (ROK) and the Democratic People's Republic of Korea (DPRK).

Trump earlier invited DPRK leader Kim Jong Un for a handshake and say "hello!" on the highly fortified DMZ, after attending the Group of 20 (G20) summit in Osaka, Japan.

Trump said Kim has responded to the offer and was "very receptive" to the idea, and he would feel comfortable stepping across the DMZ into the DPRK. 

"I can't tell you exactly, but they did respond very favorably," he told the press. 

"We'll see. If he is there, we will see each other for two minutes," said Trump. 

Later Saturday, when he was asked about his meeting at a dinner with ROK President Moon Jae-in in Seoul, he said: "We're gonna see. They're working things out right now."

Moon, who will also be going to the DMZ on Sunday, held his first two summits with Kim last year in Panmunjom, the truce village on the ROK-DPRK border. 

Choe Son Hui, the first vice minister of the DPRK Foreign Ministry, said Saturday that the proposed meeting between the leaders of the DPRK and the U.S., if it happens, would serve as a meaningful occasion to further deepen their personal ties.

Choe said the meeting as proposed by Trump is "a very interesting suggestion, but we have not received an official proposal in this regard" from the United States.

Kim has held two summits with Trump, the first in Singapore last year and the second in Hanoi, Vietnam in February. The denuclearization negotiations between Pyongyang and Washington are on hold since the Hanoi summit ended without a deal.