Donald Trump may not visit the demilitarized zone between North and South Korea, breaking with what has become a rite of passage for US presidents seeking to demonstrate America's resolve to face down Pyongyang.
Most previous US presidents have visited the eerie sliver of land that separates US and South Korean troops from their North Korean adversaries.
"There are certain elements of the schedule that are still being worked out," said a senior administration official.
Trump has instead been invited by the government in Seoul to visit Camp Humphreys, south of the South Korean capital and away from the DMZ.
"Security is not a concern. The president is most likely going to be visiting Camp Humphreys, it's going to be very difficult for him to have time to visit both," the official said.
All recent presidents, except one-term commander-in-chief George H.W. Bush, have visited the DMZ.
But it would not be unheard of for the mercurial Trump to change plans at the last moment.
The frontier, which is 2.5 miles (four kilometers) wide, spreads from sea to sea and is just a short distance from Seoul.
For the most part, it is a chilling mix of near-empty farmland, forest, wire fencing, watchtowers and turrets, all set against a soundtrack of propaganda blasted from both sides.
- North Korea nuclear concerns -
The area has been guarded by both North Korea and the US-led United Nations Command since the Korean War ended with an armistice in 1953.
Despite its name, the DMZ separating the two Koreas is one of the world's most heavily-militarized frontiers, bristling with watchtowers and landmines.
In April, Vice President Mike Pence visited, declaring that standing with US forces in Korea, along with "courageous soldiers from the Republic of Korea is a message of resolve."
Trump will be in South Korea in early November as part of a five-nation Asia visit that is set to be dominated by concerns about North Korea's nuclear and ballistic missile programs.
Since coming to office, Trump has ratcheted up pressure on North Korea, insisting it must get rid of nuclear weapons. That is unlikely to happen, resulting in a dangerous standoff.
A bellicose Trump used his maiden address to the UN General Assembly in September to warn "Rocket Man" Kim Jong-Un that he will "totally destroy" North Korea if it threatens the United States or its allies.
Trump will arrive in Japan on November 5, heading on to South Korea, China, Vietnam and the Philippines.
His visit also comes as leaders in Japan and China consolidate their power.
Prime Minister Shinzo Abe this week won a huge electoral victory that would allow him to change Japan's pacifist constitution -- a move that could change the balance of power in the region.
And Chinese leader Xi Jinping declared a "new era" in for his country, as he secured another term in power and enshrined his thinking in Communist Party doctrine.