China’s Vice Foreign Minister Sun Weidong has made grave complaints to the South Korean envoy on the South Korean president’s “erroneous” statements against Taiwan, the Chinese foreign ministry said on Sunday.

South Korean President Yoon Suk Yeol told Reuters in an exclusive interview that growing tensions around Taiwan were caused by attempts to change the status quo by force, and that he opposed such a shift.

“The Taiwan issue is not simply an issue between China and Taiwan but, like the issue of North Korea, it is a global issue,” Yoon said.

Yoon’s remarks are “totally unacceptable,” Sun said, according to a Chinese foreign ministry statement.

“The South Korean leader made no mention of the One China principle but equated the Taiwan issue with the Korean Peninsula issue,” Sun said.

“Both North and South Korea are sovereign states that have joined the United Nations. It is a well-known fact that the Korean Peninsula issue and the Taiwan issue are completely different in nature and in latitude and longitude and are not comparable at all.”

China says democratically ruled Taiwan is part of its own territory, a position Taipei strongly rejects, and demands that countries with which it has ties must adopt its position that Taiwan is Chinese territory.

Sun’s complaint followed criticism from the Chinese foreign ministry last week that South Korea should “prudently” handle matters related to Taiwan. South Korea hit back by summoning China’s ambassador to protest at Beijing’s remarks.