MANILA, Philippines -- The notoriously foul-mouthed leader of the Philippines lashed out Wednesday at Kim Jong Un, warning that the North Korean "maniac" was threatening all of Asia with nuclear war by "playing with dangerous toys."

Speaking at a separate event just before hosting an ASEAN Regional Forum of Southeast Asian leaders in his country, Philippine President Rodrigo Duterte lashed out at Kim in a speech, saying he has a kind-looking face but is really a "fool," a "son of a bitch," and disturbed.

"He's a maniac. If he commits a mistake, then the Far East will become an arid land," Duterte told people at the Philippines internal revenue service. "It must be stopped, this nuclear war."

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The ASEAN foreign ministers were expected to express their grave concern over North Korea's recent intercontinental ballistic missile (ICBM) tests at Monday's ASEAN summit, a security-focused gathering also attended by their U.S., Russian, Chinese, South and North Korean and Japanese counterparts.

The U.S. military continued early Wednesday morning to demonstrate the readiness of its own nuclear-capable long-range missile arsenal in the wake of the North's second ICBM test on Friday. An unarmed Minuteman III missile was test launched from Vandenburg Air Force Base in California overnight -- the second such U.S. test in four days.

On Monday, President Donald Trump promised to hold North Korea accountable for its aggressive missile and nuclear tests of the past year, saying his administration was "gonna be able to handle them. It will be handled."

Japan's ambassador to the United Nations has said he expects the Security Council to draft a new sanctions resolution against North Korea within days.