U.S. Vice President Joe Biden is in South Korea amid tensions over China's new Air Defense Identification Zone, or ADIZ.
Biden will meet Friday in Seoul with South Korean President Park Geun-hye before giving a speech on U.S. regional policy at Yonsei University.
The talks are likely to cover China's ADIZ and North Korea's nuclear program.
Last month, the International Atomic Energy Agency said activity had been observed at a North Korean nuclear reactor consistent with an effort to restart it. Regional powers, including China and the U.S., have recently stepped up efforts to restart talks on ending Pyongyang's nuclear weapons programs.
Air defense identification zones claimed by South Korea, China and Japan
Biden arrived in Seoul from Beijing, where he said China's ADIZ has created "significant apprehension" in the region.
The U.S., Japan and South Korea have all rejected the new zone in the East China Sea.
China said the zone was in accordance with international law and that the U.S. should take an "objective and fair attitude" about it.
Biden told a group of U.S. business leaders in Beijing Thursday he was "very direct" about the matter during his talks with Chinese President Xi Jinping.
But the vice president said conflict between Beijing and Washington was not inevitable, despite occasional disagreements.
"We are trying to build a new kind of relationship between major powers, one that is different, one that is defined by constructive cooperation, healthy competition, and a shared respect for an agreed-upon new set of rules of the road in international norms for the 21st century," he said.
Seoul is the last stop on Biden's week-long Asia tour.
On his first stop in Japan, Biden suggested establishing "confidence building measures, including emergency communications channels" to help reduce tensions.
The U.S., Japan, and South Korea have all sent military planes to the region in recent days, defying China's demand that 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.
Biden said Thursday that China must take steps "to reduce the risk of accidental conflict and miscalculation" and refrain from making moves that increase tension.
He also addressed other issues of contention between the U.S. and China. Specifically, he spoke of a "profound disagreement" over China's treatment of U.S. journalists.
Many U.S. and other foreign journalists have complained of restrictions following their publication of material that offended Beijing. Some have called for U.S. officials to address the matter with Chinese leaders.
When asked about Biden's comments, Chinese foreign ministry spokesman Hong Lei said China "has always managed foreign reporters and media in accordance with rules and the law" and that it has provided an "extremely convenient atmosphere" for them in recent years.