WASHINGTON (AP) — The Trump administration is pulling the plug on a decades-old nuclear arms treaty with Russia, lifting what it sees as unreasonable constraints on competing with a resurgent Russia and a more assertive China. The move announced Friday sets the stage for delicate talks with U.S. allies over potential new American missile deployments.

In explaining his decision, which he had foreshadowed months ago, President Donald Trump accused Moscow of violating the 1987 Intermediate-Range Nuclear Forces treaty with "impunity" by deploying banned missiles. Moscow denies it is in violation a...