WASHINGTON — President Trump has ordered the Pentagon to prepare options for drawing down American troops in South Korea, just weeks before he holds a landmark meeting with North Korea’s leader, Kim Jong-un, according to several people briefed on the deliberations.

Reduced troop levels are not intended to be a bargaining chip in Mr. Trump’s talks with Mr. Kim about his weapons program, these officials said. But they acknowledged that a peace treaty between the two Koreas could diminish the need for the 28,500 soldiers currently stationed on the peninsula.

Mr. Trump has been determined to withdraw troops from South Korea, arguing that the United States is not adequately compensated for the cost of maintaining them, that the troops are mainly protecting Japan and that decades of American military presence had not prevented the North from becoming a nuclear threat.

His latest push coincides with tense negotiations with South Korea over how to share the cost of the military force. Under an agreement that expires at the end of 2018, South Korea pays about half the cost of the upkeep of the soldiers — more than $800 million a year. The Trump administration is demanding that it pay for virtually the entire cost of the military presence.