"Just landed - a long trip, but everybody can now feel much safer than the day I took office", he tweeted.
Interested in North Korea?
Illustrative: US Army M1-A2 tanks fire during US-South Korea joint military live-fire drills at Seungjin Fire Training Field in Pocheon, South Korea, near the border with North Korea, April 26, 2017.
Pompeo added that Trump was "incredibly clear" to Kim about when the USA would lift the sanctions.
Trump later told a news conference he would end joint U.S.
"With getting strong support from Mr. Trump, (Japan) is determined to settle the issue" through direct negotiations with North Korea, Chief Cabinet Secretary Yoshihide Suga told a news conference on Wednesday. Kim is now promising to work toward a denuclearized Korean Peninsula.
"They understand what we are doing".
He is known to have stopped over at airbases in Guam and Hawaii to encourage USA forces and is expected to arrive at the White House sometime Wednesday morning.
Why should the United States station 30,000 troops in Korea if Korea is at peace?
In the brief, four-point joint statement signed at the summit, North Korea committed "to work toward complete denuclearization of the Korean Peninsula" - a promise it has made and reneged on several times in the past 25 years.
North Korea's leader Kim Jong Un listens to U.S. President Donald Trump as they meet in a one-on-one bilateral session at the start of their summit at the Capella Hotel on the resort island of Sentosa, Singapore, June 12, 2018.
And after Trump made a fat joke and showed Kim the inside of his limo, they signed their "historish agreement", he said.
Logically, Trump should receive no credit if you believe he brought us to the brink of war with North Korea and then pulled us back. To secure Kim's signature on the Singapore agreement, Washington jettisoned its historic focus on North Korean human rights abuses - a question officials in Tokyo will likely raise with Pompeo in coming days.
"We needed to alleviate this kind of paranoia of North Korea on their own national security", he said.
North Korea could begin giving up its weapons today if it wanted to, but it instead has insisted on staging performances of denuclearization rather than on inviting worldwide inspectors to verify its progress.
Trump said, 'We're flying planes in from Guam, we're bombing empty mountains for practice. The next military exercise is scheduled for August, and in years past, has drawn thousands of troops from the U.S., South Korea and other countries.
"Kim Jong Un and Trump had the shared recognition to the effect that it is important to abide by the principle of step-by-step and simultaneous action in achieving peace, stability and denuclearization of the Korean Peninsula", state media outlet KCNA reported.
Trump's announcement minutes after the summit's conclusion that he would halt the "provocative" joint military drills were a shock to South Korea and caught much of the USA military off guard, too. Trump cast that decision as a cost-saving measure, but also called the exercises "inappropriate" while talks continue.
But the president's change in approach - to reset the relationship before denuclearisation, not after, is one that the former Director of National Intelligence James Clapper has welcomed: it was necessary, he says, to create a new dynamic in which talks might progress. US officials said it was unclear what types of training involving USA and South Korean troops might cross into Trump's now forbidden zone of "war games".