U.S. Vice President Joe Biden has rejected China's new air defense zone in the East China Sea, saying it raises tensions in the region and the possibility of miscalculation.
In a speech Friday at a university in Seoul, Biden said the United States does not recognize the Air Defense Identification Zone, or ADIZ.
He said it will have no effect on American operations.
China has dismissed calls by officials in Washington, Tokyo and Seoul to roll back the defense zone, which Beijing says is in accordance with international law.
Biden made his remarks on the last stop of a week-long Asia tour, which has been dominated by tensions involving the ADIZ. He also spoke about the issue during a meeting in Seoul Friday with South Korean President Park Geun-Hye.
Last month, China extended its aviation security area in the East China Sea over islands disputed with Japan and a reef disputed with South Korea. China said all aircraft intending to enter the zone must first submit a flight plan, with Chinese officials reserving the right to deny access.
On Thursday in Beijing, Biden said China's new defense zone has created "significant apprehension" in the region.
The U.S., Japan and South Korea have rejected the new zone. Those three countries have sent military planes into the zone in recent days, defying China's demand they notify Beijing beforehand. China has not interfered with the flights but has scrambled fighter jets to the area, heightening concerns about a possible miscalculation in the air.
On Friday, Biden also reaffirmed a U.S. plan to re-focus on the Asia-Pacific and urged North Korea to give up its nuclear weapons.
The vice president said there should be no doubt about the U.S. commitment to preserving balance in the region. He also said the U.S. and the international community have made it clear to North Korean leader Kim Jong-un that they will not tolerate or accept nuclear weapons in North Korea.