President Trump on Monday ramped up his war of words against North Korea, saying the U.S. and its Asian allies “will not stand” for its nuclear aggression.

Speaking in Tokyo, Trump denounced Pyongyang as a “threat to the civilized world” and demanded that North Korean leader Kim Jong Un halt development of nuclear weapons and missile tests, some of which have been fired over Japanese airspace.

“The era of strategic patience is over,” Trump said, standing alongside Japanese Prime Minister Shinzo Abe. “Some people say my rhetoric is very strong, but look what has happened with very weak rhetoric over the past 25 years.”

The president Monday showed he is not planning to tone down his rhetoric against North Korea during his five-nation trip to Asia, a region on edge over Kim’s nuclear activities.