The biggest threat facing the U.S. today comes from North Korea’s missile advances, and the danger is growing, Army Chief of Staff Gen. Mark A. Milley said.

Speaking at the National Press Club, Milley said North Korea’s successful Fourth of July test of an intercontinental ballistic missile shows the rogue nation has advanced faster than expected toward its threat of being able to reach the U.S. with a nuclear warhead. “North Korea is a significant threat,” Milley said.

The U.S. is trying economic and diplomatic efforts to prevent North Korea from expanding its capabilities, Milley said. “The military fully supports those. We want those to succeed,” he said. “There is still time left for this to succeed.”

The Army supports the broad campaign to pressure North Korea to drop its ballistic missile program, he said. “We are fully supportive of the efforts of the secretary of state and the Department of State to bring this to a peaceful solution, however, time is running out at bit. North Korea is extremely dangerous, and it gets more dangerous as the weeks go by.”