Taiwan's President Tsai Ing-wen accused China of "serial acts of suppression" and "dollar diplomacy" after Burkina Faso became the second country in a month to break off diplomatic ties with the island in favor of Beijing.
The move by the African nation, which was welcomed by China, came after the Dominican Republic announced it had severed ties with Taiwan, switching its allegiance to Beijing.
China refuses to maintain diplomatic relations with any country that recognizes Taiwan, a self-governed and democratic island off China's southeastern coast that Beijing considers an integral part of its territory.
Taipei reacted angrily to the news, which left the island with 18 diplomatic allies around the world -- mostly small and poor countries in the Pacific and the Caribbean.
"This is a warning to the Chinese government: This behavior is detrimental to cross-strait relations and China's international image, and does nothing to ease the international community's concerns about China," President Tsai told reporters in an unusually strongly worded statement late Thursday.
"China's suppression will only make Taiwan's partnerships in the international community even closer. We will never give in," she added.
The foreign ministry in Beijing said that China appreciates Burkina Faso's decision, according to Xinhua, China's official news agency.
"We welcome Burkina Faso to join in China-Africa friendly cooperation as soon as possible on the basis of the one-China principle," it said in a statement.
Taiwan minister offers to quit
Taiwan Foreign Minister Joseph Wu said he had offered his resignation to President Tsai. He added that his country will also halt all bilateral cooperative projects, cut all assistance to Burkina Faso, and pull out its diplomatic staff and technical missions from the African country.
Beijing and Taipei have a long history of rivalry in their efforts to gain economic opportunities and diplomatic support from governments around the world. With China's rapidly rising economic and political might, however, the race is increasingly tilting in China's favor.
Last year, in another major blow to Taiwan, Panama switched diplomatic recognition from Taipei to Beijing. There also have been suggestions that the Vatican -- Taiwan's most symbolically important remaining ally -- may follow suit.
China and Taiwan -- officially the People's Republic of China and the Republic of China, respectively -- separated in 1949 following the Communist victory on the mainland after a civil war.
Although both Beijing and Taipei view the island as part of China, neither government recognizes the legitimacy of the opposing side.
Washington has close unofficial ties with Taiwan and provides the island with arms under the Taiwan Relations Act, but the US has formal diplomatic relations only with Beijing.
In the past few months, the Trump administration angered Beijing by authorizing US manufacturers to sell submarine technology to Taiwan, as well as enacting the Taiwan Travel Act to encourage official visits between the US and the island.
Earlier this month, the White House publicly admonished China for warning foreign airlines to change how they identify Taiwan and other areas on their websites.
More than 30 airlines - including some US carriers - were recently told by the Civil Aviation Administration of China to remove any information suggesting Taiwan, Hong Kong or Macau are not part of China.
Chinese media reported this week that Japanese retailer Muji was fined 200,000 yuan ($31,000) by Shanghai authorities for importing a batch of coat hangers wrapped in packaging that described Taiwan as a country.
"China's serial acts of suppression against Taiwan in the diplomatic sphere clearly show their unease and lack of self-confidence," said President Tsai in her statement on Burkina Faso's diplomatic desertion.