WASHINGTON—The U.S. remains on a path to withdraw from a landmark nuclear-arms-control agreement with Russia, citing alleged violations by Moscow, but continues to consult with its allies on the decision, the Trump administration’s top intelligence official said.

“We are still pursuing this issue,” Director of National Intelligence Dan Coats told reporters on Tuesday. He said he will brief European allies at a North Atlantic Treaty Organization meeting in Brussels this week “in terms of what the threat [from Russia] is and...