Taiwan President Lai Ching-te has cancelled a trip to the southern African nation of Eswatini, accusing China of putting pressure on other countries to bar his aircraft from flying over their territories.

Seychelles, Mauritius and Madagascar revoked Lai's flight permits after "intense pressure" and economic coercion from China, said a Taiwan official. China denied coercion, while praising the three Indian Ocean nations saying it had "high appreciation" for them.

This is the first publicly known instance where Taiwan's leader has had to cancel a trip due to revoked flight permits.

Eswatini is one of 12 nations which are diplomatic allies of Taiwan and the only one in Africa.

According to news agency Reuters, Seychelles and Madagascar said they took the decision because they do not recognise Taiwan.

Taiwanese officials claimed that the three African countries revoked the flight permits "unexpectedly and without prior notice".

China adheres to the "one China" principle in which Beijing asserts sovereignty over Taiwan, though many in Taiwan consider themselves to be a sovereign nation.

Beijing sees the self-governed island as a breakaway province that will eventually be part of the country, and has not ruled out the use of force to achieve this.

The Chinese government has been vocal in its dislike of Lai, whom it has previously described as a "troublemaker" and a "destroyer of cross-strait peace".

In a statement on X, Lai criticised China's "coercive actions", saying that it "exposed the risks authoritarian regimes pose to the international order".

"No amount of threats or coercion will shake Taiwan's resolve to engage with the world."

The government of Eswatini, formerly known as Swaziland, said it was regrettable that Lai was unable to visit, but that this would not "change the status of our longstanding bilateral relationship", according to reports.

Lai was due to spend 22 to 26 April in Eswatini to attend celebrations marking the 40th anniversary of King Mswati III's accession and the king's birthday.

Taiwan said that a special envoy will be appointed to attend the celebrations on Lai's behalf.

At a press briefing on Wednesday, a spokesperson of the Taiwan Affairs Office of the State Council said Beijing "appreciated the position and actions of the relevant countries in upholding the one-China principle".

China's Ministry of Foreign Affairs also said that it was "clear...[that] the so-called 'President of the Republic of China' no longer exists in the world", in a reference to Lai's official title in Taiwan.

Some in the US have criticised Seychelles, Mauritius and Madagascar, with the House Foreign Affairs Committee Majority saying they "stood with Taiwan against this blatant coercion" in a post on X.

US Senator Ted Cruz also criticised Mauritius, saying it seemed "determined to ally with the Chinese Communist Party".