Trump was aboard Marine One en route to the DMZ but was grounded after about 18 minutes of flight.
South Korean President Moon Jae-in was scheduled to join Trump at the DMZ in a show of unity, White House press secretary Sarah Sanders told reporters Wednesday morning. The joint visit would have been the first for a US and South Korean President at the DMZ, Sanders said, calling it a "historic moment."
"The effort shows the strong and importance of the alliance between the two countries," Sanders said.
Trump was disappointed and frustrated by the failed attempt, Sanders told reporters, adding that the trip had been quietly planned before Trump left Washington for his trip through Asia.
The White House had previously said Trump was not going to visit the DMZ due to limited time
in the President's hectic schedule and said he would instead visit Camp Humphreys, a joint US-South Korean military base that Trump visited on Tuesday.
One senior White House official said he believed trips to the DMZ had become "a bit of a cliché," noting that top US officials including Vice President Mike Pence, Secretary of State Rex Tillerson and Defense Secretary James Mattis have all visited the tense border this year.
Asked about the description earlier this month of a DMZ trip as "cliché," a senior administration official acknowledged on Tuesday that symbolism -- however overworked -- is an essential component of the presidency.
"Symbols are important," the official said, noting that Trump himself was intent on visiting the heavily fortified border as a show of strength against North Korea.
The official said there was a debate within the administration about making a visit and the potential for the stop to heighten tensions with Kim Jong Un. But they were reassured by Moon's support and his willingness to meet Trump there.
A heavy fog limited visibility in the air, with helicopter pilots losing visibility of the other helicopters in the President's airborne motorcade, Sanders said. The President and his entourage waited for nearly an hour on the ground in hopes the weather would improve, but were not able to make a second attempt.
The visit took place in secret, with reporters traveling with the President told they could not report on the trip until after Trump had touched back down in Seoul. And officials took extra measures to keep the trip as secret as possible.
"This is where we're going," Sanders told reporters early Wednesday morning, holding up a piece of notepaper scrawled with the letters "DMZ."
Trump was aboard Marine One with his chief of staff Gen. John Kelly, his national security adviser Lt. Gen. H.R. McMaster, Tillerson and Gen. Vincent Brooks, the commander of US Forces Korea.
Trump on Wednesday will formally articulate his views of a region on edge during an address at South Korea's National Assembly.
Trump's two-day stop in South Korea is part of a larger tour of Pacific nations, where he has met with other world leaders in the region including Japanese Prime Minister Shinzo Abe.