U.S. President Donald Trump rallies with supporters at Elko Regional Airport in Elko, Nevada, U.S. October 20, 2018. REUTERS/Jonathan Ernst

WASHINGTON (Reuters) - President Donald Trump warned on Monday that the United States intended to build up its arsenal of nuclear weapons to pressure Russia and China.

Speaking to reporters, Trump repeated his contention that Russia was not abiding by the 1987 Intermediate-Range Nuclear Forces Treaty, which he has threatened to abandon.