China is opposed to any official exchanges and military contacts between the United States and Taiwan, Foreign Ministry spokesman Geng Shuang said on Wednesday, urging the US to handle the Taiwan question cautiously and prudently.

Geng made the remarks in a daily news conference, responding to comments a US defense official made on Tuesday.

The US Deputy Assistant Secretary of Defense Abraham Denmark said in the Project 2049 Forum in Washington that Taiwan should increase defense spending to "deter" "threats" from the Chinese mainland, Reuters reported.

The US President-elect Donald Trump took a phone call from Taiwan leader Tsai Ing-wen in early December and said on Sunday the US doesn't have to be bound by the one-China policy.

Geng urged the US on Wednesday to observe the one-China policy and the three China-US joint communiques.