Could Mr. Kim borrow a plane? Perhaps, but not without a significant dent to his well-established hubris. Could the meeting be held close enough for him to take a train, as he did last month in a secretive visit to China? In theory, though viable options are few. Could Mr. Trump instead travel to Pyongyang, the North Korean capital, thus nullifying the issue? He is almost certainly unwilling to stomach the appearance of showing deference to Mr. Kim.

“It’s really hard if you only have a 2,000-mile radius,” said David H. Rank, who previously served as the acting United States ambassador to China.

Locations in the United States and Europe were in the running, a senior administration official said on Wednesday, though the situation was fluid. Here are some options being discussed:

Europe

In theory, a neutral location like Sweden or Switzerland would be ideal. Both maintain diplomatic relations with the United States and North Korea and have signaled a willingness to facilitate the meeting.

Those locales have been the sites of some of the most significant diplomatic achievements in history — Geneva hosted the 1985 meeting between President Ronald Reagan and the Soviet leader Mikhail S. Gorbachev. It could provide the dramatic backdrop that both leaders appear to crave.

But to get there, one needs a plane.

“He’s not going to fly commercial,” Ms. Terry said of Mr. Kim.

American Territory

With the expected range of Mr. Kim’s planes, a trip to Hawaii or Guam, the closest United States territory to North Korea, would almost certainly require a refueling stop or a borrowed plane. Korea experts call that an indignity that Mr. Kim would not accept.