U.S. President Donald Trump has recently mused to confidants about withdrawing from a long-standing defense treaty with Japan that he thinks treats the United States unfairly, according to three people familiar with the matter.

Trump regards the accord as too one-sided because it promises U.S aid if Japan is ever attacked but doesn't oblige Japan's military to come to America's defense, the people said. The treaty, signed more than 60 years ago, forms the foundation of the alliance between the countries that emerged from World War II.

Even so, the president hasn't taken any steps toward pulling out of the treaty, and administration officials said such a move is highly unlikely. All of the people asked not to be identified discussing Trump's private conversations.