TAIPEI, TAIWAN - A U.N. aviation agency has not invited Taiwan to its September conference in Canada, the latest sign that China is putting more pressure on Taiwan's new government.

Taiwan's Ministry of Foreign Affairs said Friday that it had not received invitations from the International Civil Aviation Organization (ICAO), as Taipei officials had hoped.

"For such a result, our government expressed strong regret and dissatisfaction," said Taiwanese Foreign Minister David Lee, whose government wanted officials to participate in the September 27 ICAO Conference in Montreal, Quebec.

Taiwanese President Tsai Ing-wen condemned the decision as "extremely unfair for Taiwan, and a major loss of international aviation safety."

Taiwan is not a member of the United Nations, which recognizes Beijing's one-China policy.

"ICAO follows the United Nations' one-China policy," the agency's communications chief, Anthony Philbin, told Reuters via email.

ICAO officials say they invited Taiwan to their last conference in 2013, only because China had asked Taiwan to be invited.

"While arrangements had been made for their attendance at the last [38th] session of the assembly, there are no such arrangements for this one," an ICAO spokesperson said.

Taiwan ‘inseparable part of China’

Since Tsai and her Democratic Progressive Party took power in Taiwan, mainland China has increasingly pressured Taiwan to concede to Beijing's interpretation of the one-China principle, which includes Taiwan as part of China.

As an "inseparable part of China," said Chinese Foreign Ministry spokesman Lu Kang, Taiwan has no right to participate in the assembly, and Taipei's attendance in the past was based on "temporary arrangements."

"At present, our position is extremely clear," Lu told a regular news briefing. "The prerequisite for Taiwan to participate in any international activity is for it to agree to the one-China policy and for this to be resolved through consultation."

Taiwan’s president slammed Beijing for, as she put it, placing geopolitics ahead of the basic human right of aviation safety.

"People should not be deprived of rights because they have refused to accept the limits of a certain non-democratic framework," she said.

Lee also said that Taiwan's participation in ICAO "should not be subjected to the restrictions of any political framework," calling ICAO's decision damaging to its own neutrality and integrity as an international organization.