The head of the U.S. military’s Pacific Command on Wednesday urged Russia and China to step up efforts in reining in North Korea and persuade the reclusive state to halt its nuclear weapons program and related provocations.

“The dangerous behavior by North Korea is not just a threat to the Korean Peninsula,” Adm. Harry Harris said at an event in Tokyo, referring to Pyongyang’s latest test launch of a new ballistic missile on Sunday.

“It’s a threat to Japan. It’s a threat to China. It’s a threat to Russia. Let me say that again, it’s a threat to Russia,” Harris said.

The commander included Russia in a list of “responsible” contributors to international security, which must work together to “bring (North Korean leader) Kim Jong Un to his senses, not to his knees.”

Harris said during meetings Tuesday in Tokyo with Prime Minister Shinzo Abe and Defense Minister Tomomi Inada that North Korea’s acts, such as a series of ballistic missile and nuclear tests, were unacceptable.

Harris declined to say whether the U.S. military has sent ships or aircraft within what China claims to be its territory near disputed islands in the South China Sea since President Donald Trump took office in January.

But Harris signaled the U.S. military could continue with freedom of navigation operations in the waters.

“I have believed and advocated for the necessity for the United States, and our friends and allies and partners, by the way, to continue to exercise our rights on international law,” Harris said.

“We should be able to fly, sail and operate wherever international law allows.”.

During former President Barack Obama’s administration, the U.S. sailed ships and flew aircraft to areas within 12 nautical miles of locations in the Spratly Islands and Paracel Islands over which China claims sovereignty, drawing sharp reactions from Beijing.

Harris played down recent reports that Chinese Ambassador to the U.S. Cui Tiankai called on Trump’s administration to dismiss Harris.

“I don’t have an opinion” on the story, Harris said during a question and answer session at the event. “Ask the esteemed ambassador directly.”

Harris reiterated the U.S. was committed to defending the Japan-administered Senkaku group of islets, which China claims in the East China Sea, under Article 5 of the U.S.-Japan security treaty.

Harris is the first Japanese-American to head the Pacific Command.