Updated

U.S. officials are discussing North Korea with key Asian powers, as tensions stoked by a recent missile test and the poisoning death of its leader's brother threatened to intensify with upcoming military drills.

North Korea's rapid progress toward acquiring a nuclear-tipped missile that could strike the U.S. mainland poses one of the sternest national security challenges for President Donald Trump.

U.S. envoy on North Korea policy, Joseph Yun, huddled Monday with his Japanese and South Korean counterparts, continuing U.S. efforts to get its main allies in Asia to cooperate.

Chinese State Councilor Yang Jiechi (YAHNG jee-uh-CHERR) will also discuss North Korea. He is in Washington on Monday and Tuesday for meetings with senior U.S. officials. He is the first senior Chinese official to visit the U.S. since Trump took office.