The US says its National Security Advisor met with China's top diplomat in Luxembourg on Monday.
Among the topics discussed were Taiwan, North Korea and Ukraine.

The White House issued a statement saying the meeting between Jake Sullivan and Chinese Communist Party Politburo Member Yang Jiechi included "candid, substantive, and productive discussion of a number of regional and global security issues, as well as key issues in US -China relations."

White House Press Secretary Karine Jean-Pierre said that Sullivan understood the importance of maintaining open lines of communication to manage competition between the two countries.

A senior US administration official said that Sullivan clearly expressed concern about China's repressive and aggressive behavior and remarks concerning Taiwan.

On Sunday, China's defense minister said the country will fight to the finish if someone tries to separate it from Taiwan, in an apparent warning against the United States increasing its involvement in Taiwan.