China firmly opposes any form of official contact and military exchange between the United States and Taiwan.

BEIJING, Dec. 14 (China) -- China on Thursday opposed Taiwan-related terms in the National Defense Authorization Act of the United Statesfor the 2018 fiscal year, which was recently signed into law by President Donald Trump.

"Even though the Taiwan-related clauses in relevant U.S. act are not legally binding, they severely violate the one-China policy and the principles of the three China-U.S. joint communiques, displaying interference in China's internal affairs," said Chinese Foreign Ministry spokesman Lu Kang at a press briefing.

"China is resolutely opposed to this, and has already lodged stern representations with the U.S. government," said Lu.

One-China policy is the political foundation of China-U.S. relations, Lu reiterated, saying that China firmly opposes any form of official contact and military exchange between the United States and Taiwan.

He urged the U.S. to recognize the gravity of the damage the clauses may cause, and to properly handle Taiwan-related issues so as not to harm China-U.S. cooperation, as well as peace and stability across the Taiwan Strait.

President Donald Trump signed the National Defense Authorization Act for the 2018 fiscal year into law Tuesday, some clauses of which authorize the possibility of mutual visits by navy vessels between the United States and Taiwan.