BEIJING — Burkina Faso and China formally established diplomatic ties on Saturday, days after the West African nation broke off relations with Taiwan, the self-governing island that Beijing has been trying to isolate on the global stage.
Burkina Faso’s decision was the latest blow to Taiwan, which Beijing considers part of its territory. The island is now left with 18 diplomatic allies — many of them poor nations in Central America and the Pacific, like Belize and Nauru; only one is in Africa, the tiny kingdom of Swaziland.
It was the second ally to break with Taiwan in less than a month, as China’s economic clout and geopolitical influence have made it difficult for countries to maintain alliances. The Dominican Republic established diplomatic relations with Beijing this month, citing hopes for improved commercial ties.
The Chinese Foreign Ministry said a document establishing diplomatic ties was signed on Saturday in Beijing between Wang Yi, the state councilor and foreign minister, and Burkina Faso’s foreign minister, Alpha Barry.
On Thursday, in a statement about the decision to break with Taiwan, Mr. Barry made no direct mention of China, saying only, “The evolution of the world and the socio-economic challenges of our country and region push us to reconsider our position.”
Beijing claims Taiwan as its own territory under its “One China” principle, and has long refused to have diplomatic relations with any country that officially recognizes Taiwan. It has been ratcheting up pressure since President Tsai Ing-wen, whose party has traditionally favored independence for Taiwan, took office two years ago.
On Friday, Ms. Tsai said on Twitter that “China’s growing pressure will only strengthen other countries’ support for us.” She added, “We will never back down.”
Taiwan’s foreign minister, Joseph Wu, said he had offered his resignation to the president, saying that Taiwan cannot compete with China’s financial resources.
“I, along with our country’s people, feel sad, angry and regretful,” he said. “China grabbing our allies and giving us pressure in the diplomatic space will not shrink the distance across the strait and will not let cross-strait relations walk on a peaceful, friendly path.”
It was unclear if Ms. Tsai had accepted his resignation.
The Finance Ministry said, however, that it would end its aid programs in Burkina Faso and that Taiwan would close its embassy there.
China is Africa’s largest trade partner, with huge investments in mining, construction and banking, though it had been less active to date in Burkina Faso. It is set to host a summit meeting of African leaders in September in Beijing, where it will most likely offer new pledges of aid and preferential loans.
Burkina Faso is the fourth country to cut ties with Taiwan since Ms. Tsai came to office, following the Dominican Republic, São Tomé and Príncipe and Panama. All have established a relationship with China.
The Vatican cold be next, analysts say, as the Holy See and China edge closer to an accord on the appointment of bishops there.
Some countries have switched back and forth between Beijing and Taipei several times. This is the second time Burkina Faso has cut ties with Taiwan. It previously did so in 1973, before resuming relations in 1994.