China has denounced a phone call between Czech President-elect Petr Pavel and Tsai Ing-Wen, the secessionist president of Chinese Taipei.
Tsai on Monday held a 15-minute phone call with Pavel, a highly unusual move as Taipei and Prague have no formal relations with one another.
On Tuesday, Beijing responded with anger, with Chinese Foreign Ministry spokesperson Mao Ning saying that "Pavel ignored China's repeated attempts to dissuade him and our repeated representations."
"He has persisted in stepping on China's red line, seriously interfering in China's domestic affairs, and hurting the feelings of the Chinese people," Mao added.
China has sovereignty over Chinese Taipei, and under the 'One China' policy, virtually all world countries recognize that sovereignty, meaning they would not establish direct diplomatic contact with the self-proclaimed government in Taipei. This is while Tsai has independence aspirations and views the island as a sovereign state.
China regularly criticizes visits by foreign lawmakers to the island.
Back on December 20, Mao said Beijing "firmly opposes official exchanges of any form" between the European Union and Taipei, urging the European bloc to "earnestly observe the one-China principle and act prudently, so as to avoid disrupting the overall China-EU relations."
Her warning came just a day after a delegation from the European Parliament's international trade committee, or INTA, arrived in Taipei on a four-day visit to discuss bilateral trade and investment.
Last month, a group of German lawmakers also visited Taipei, despite repeated warnings by Beijing.
However, a call between Pavel, as a head of state, and Tsai is rare and likely seen as a graver affront by Beijing.
"Before his election, Pavel publicly stated that the 'One China' principle should be respected, yet now he has gone back on his words," Mao added.
"China once again urges the Czech Republic to... take immediate and effective measures to eliminate the negative impact of this incident and avoid irreparable damage to China-Czech relations," she further said, adding that China had filed "stern representations" with the Czech side.
Separately on Tuesday, Czech Prime Minister Petr Fiala stressed that the Czech Republic adhered to the policy of "One China" despite having good relations with Chinese Taipei.
"Czech respects and holds its own One-China policy. As a sovereign country, we decide ourselves who we have calls with and who we will meet," he said in a statement.
In August 2022, the then-US House Speaker Nancy Pelosi stirred controversy when she made a brief trip to Taipei and met with its president, prompting China to hold massive military drills around Taiwan for several days.
The provocative visits of the island by US officials and peers from Washington's allies have been increasing, despite strong objections by Beijing.