South Korea hosts the third-largest number of American troops outside the U.S.—after Japan and Germany—stationed there to help defend Seoul against threats from nuclear-armed North Korea and support regional efforts to counter an increasingly assertive China.

WASHINGTON—The Trump administration is weighing a withdrawal of thousands of American troops from South Korea, according to military officials familiar with the discussions, a move that could stir new anxiety among allies worried about the White House commitment to Asia.

The Pentagon pushed back Friday on a Wall Street Journal report that the Trump administration is considering withdrawing thousands of American troops from South Korea, calling the news “not true.” The Journal first reported Thursday that the Defense Department [DOD] was developing an option to pull out roughly 4,