The Chinese government expressed concerns about President-elect Donald Trump’s stance on the relationship between the U.S. and China, according to reports.

In an interview with Fox News Sunday, Trump said he might disregard the longstanding U.S. “One China” policy, which acknowledges the sovereignty of China as opposed to Taiwan and is a source of contention for China.

“I fully understand the ‘One-China’ policy, but I don’t know why we have to be bound by a ‘One-China’ policy unless we make a deal with China having to do with other things, including trade,” he said.

But Chinese Foreign Ministry spokesman Geng Shuang criticized the statement, NBC News reported.

“If the [one China policy] is compromised or interfered with, any sound and steady development in China-U.S. relations and cooperation in various fields is out of the question,” the spokesman said.