President Trump and North Korea's Kim Jong Un will start their historic summit with a one-on-one session with translators.
A U.S. official says Monday that the leaders will meet for up to two hours before an expanded bilateral meeting with their respective advisers. The official was not authorized to speak publicly about internal deliberations and insisted on anonymity.
Officials remain uncertain what will come out of Tuesday's unprecedented summit, the first of its kind between a sitting U.S. president and the leader of North Korea.
Mr. Trump has said he wants to strike a deal to get the North to give up its nuclear weapons. He also has sought to lower expectations for the meeting, saying it may be the start of a longer process.
Late Sunday night, Mr. Trump took to Twitter to write "great to be in Singapore":
Great to be in Singapore, excitement in the air!— Donald J. Trump (@realDonaldTrump) June 11, 2018
This came after a flurry of tweets about disputes over U.S. trading partners, writing that "we must put the American worker first":
Sorry, we cannot let our friends, or enemies, take advantage of us on Trade anymore. We must put the American worker first!— Donald J. Trump (@realDonaldTrump) June 11, 2018
The Associated Press contributed to this report.