China’s Foreign Minister Wang Yi expressed his disapproval of Czech Senate President Milos Vystrcil for his visiting Taiwan on Monday, August 31, to promote trade ties with the country.

On a visit to Germany on Monday, Wang told reporters that the Chinese Communist Party (CCP) would not stand idly by in the face of Milos Vystrcil’s “public provocation,” in the process criticizing the “anti-Chinese forces behind him.”

“To challenge the one-China principle on Taiwan is to make an enemy of 1.4 billion Chinese people, and is an international breach of trust,” the CCP official said. He then threatened, “We must make him pay a heavy price for his shortsighted actions and political opportunism.”

As Reuters noted, on his visit to Taipei, Vystrcil said the Czech Republic would not give in to CCP objections that it considers Taiwan a separatist province not eligible for state-to-state relations.

Vystrcil is the highest-ranking Czech politician to visit Taiwan since President Vaclav Havel did so 16 years ago. The Taiwanese government announced that Vystrcil’s visit also marked another diplomatic victory after the high-profile visit of U.S. Health and Human Services Secretary Alex Azar.

As reported by the South China Morning Post, over the years, Beijing has emphasized that its ultimate goal is to bring Taiwan’s democratic island under its rule, even if force is required. It has warned countries not to hold official exchanges with Taiwan, as they would appear to support Taiwanese sovereignty.

Czech Foreign Minister Thomas Petricek said that although the government did not support Vystrcil’s trip, Wang’s comments were too strong. He wanted an explanation, requesting a meeting with the Chinese ambassador.

“I expect that the Chinese side will explain them to us. The trip has of course an impact on relations with China, but I think that this has crossed the line,” Petricek told reporters, as reported by the CTK news agency.

According to Vystrcil, Wang’s comments were interference in the internal affairs of the Czech Republic.

“We are a free country seeking to have good relationships with all countries and I believe this will be the case in the future irrespective of the statement of the minister. And let me repeat again—this visit is by no means meant to politically confront anyone,” he said.

According to The Associated Press, Vystrcil traveled with a delegation of 89 leaders from political, business, artistic, and academic circles of the central European country on a trip aimed at strengthening contacts.

Arriving on the island Monday afternoon, Vystrcil spoke at National Chengchi University in Taiwan about the importance of supporting freedom and democracy worldwide.

“Democratic countries should also support each other while supporting other countries that are actually fighting for their democracy or that may be threatened by the strong and the powerful,” Vystrcil said. “Thus, it is our obligation to jointly support Hong Kong and it is our duty to support a free Belarus,” added according to the South China Morning Post.