"This is the first step in the process of reconciling the national after the historic reunion at the third North-South summit and bringing the North and South together", the state-run Korean Central News Agency reported, revealing the standard times of North and South Korea are now the same. But troops are not on the table.
During the inter-Korean summit, North Korean leader Kim Jong Un expressed his intention to synchronize his country's time zone with Seoul.
Speaking to reporters, Mr Trump said "a lot of things have happened" with regards to USA citizens reportedly being held in North Korea. "Stay tuned!" Trump stated via his Twitter social media account.More news: Prime Capital Investment Advisors LLC Sells 16627 Shares of Alibaba Group (BABA)
The U.S. President also denied a recent report from the New York Times which claimed he was considering reducing the number of U.S. troops in South Korea.
He said: "We now have a date and we have a location".
South Korea had also changed its clocks to move away from Japanese time in the 1950s, but eventually reverted back to Japan's time zone in the 1960s.More news: John Peterson soars into Quail Hollow lead behind pair of eagles
The last occasion was when former South Korean President Lee Myung-bak and former Chinese Premier Wen Jiabao held a summit with then Japanese Prime Minister Naoto Kan in April 2011, soon after an quake and tsunami killed over 18,000 people in Japan's northeastern coast and led to the Fukushima nuclear disaster.
And while Trump said he was not envisaging a drawdown of troops in South Korea for now - something the regime in Pyongyang has long wanted - he admitted it was a possibility in the longer term.
The latest development follows vice president Mike Pence postponing a planned trip to Brazil at the end of May to free up resources for President Trump's North Korea summit.More news: ETA ends armed campaign and political efforts for Basque homeland
"We're having very substantive talks with North Korea and a lot of things have already happened with respect to the hostages", he said. The two leaders signed a peace accord and officially ended the Korean War, which started in 1950.