Taiwan expressed "dissatisfaction and regret" over the World Health Organization's failure to invite it to attend an upcoming annual assembly in Geneva, amid diplomatic pressure from China to isolate the island.
The WHO had ignored Taiwan's repeated requests to be allowed to attend the World Health Assembly (WHA), scheduled for May 22-28, as an observer, the foreign ministry said in a statement.
Taiwan is excluded from most global groups due to Beijing's objections. China insists that Taiwan should not be treated as an independent country as it considers the island to be one of its own provinces.
Taiwan has complained that its exclusion from the WHO has hampered efforts to fight the COVID-19 pandemic.
"The WHO failed to stay neutral and professional, repeatedly ignoring the necessity and urgency for Taiwan's participation in the WHO and WHA," the ministry's statement said.
Earlier this week a WHO official said a decision over whether Taiwan would be granted observer status was likely by Monday, after the agency received a proposal from 13 member states supporting Taiwan's request to attend.
Taiwan will send a delegation to Geneva to lobby for observer status at the assembly, and to meet with counterparts from other countries on the sidelines of the forum.
Reuters could not immediately reach the WHO for a response to the ministry' statement.
China blocked Taiwan's participation after the election in 2016 of Taiwan President Tsai Ing-wen, who China views as a separatist - a charge she rejects. Taiwan had been allowed to attend the assembly from 2009 to 2016, during a period of warmer relations between Beijing and Taipei.
The US State Department said on Tuesday that Taiwan should be allowed to attend the meeting, saying the democratically governed island's exclusion at China's behest was unwarranted and a concern for global health.
Taiwan rejects China's claim of sovereignty and says only its people can decide the island's future.