The Chinese mainland has criticized Taiwan leader Lai Ching-te's visit to Eswatini as a political farce, while urging the African nation and some other individual countries to stop serving as a prop for "Taiwan independence" separatists.

The remarks came after reports said Lai arrived in Eswatini on Saturday aboard a "private jet" of the King of Eswatini. Just a day earlier, a magnitude 6.1 offshore earthquake struck off Yilan county in Taiwan, with strong tremors felt in many areas.

A Foreign Ministry spokesperson said on Saturday that Lai had ditched the people in Taiwan who were still reeling from the disaster and sneaked onto a foreign plane to "smuggle" himself out of the island, squandering taxpayers' money and performing a laughable stunt in front of the world.

"That just added yet another episode to the scandalous 'Taiwan independence' separatism," the spokesperson said.

The spokesperson said the undignified act of Lai and his like once again proves that the one-China principle has long been a basic norm in international relations and a prevailing consensus of the international community.

No matter how the Democratic Progressive Party authorities collude with external forces and keep those people in the DPP's pay, it will always be a losing cause and nothing will ever change the fact that Taiwan is part of China, the spokesperson said.

No matter how "Taiwan independence" forces try to cover up their nature or change their appearance, nothing can save their reputation or help them escape the denunciation of the international community, the spokesperson added.

"We urge Eswatini and some other individual countries to see where the arc of history bends and stop serving as a prop for 'Taiwan independence' separatists," the spokesperson said.

Eswatini is one of the 12 countries — and the only African country — that still maintain so-called "diplomatic relations" with Taiwan.

The Taiwan Affairs Office of the State Council also slammed Lai's trip on Saturday, saying his previous attempt to visit Eswatini by chartered plane had been forced to be canceled after relevant countries upheld the one-China principle.

Chen Binhua, a spokesman for the office, said Lai refused to accept the setback and traveled to Eswatini "in a sneaky manner" while Taiwan was being hit by an earthquake, exposing his indifference to people on the island and his stubborn "Taiwan independence" stance.

Chen said safeguarding peace and stability across the Taiwan Strait and leading secure and prosperous lives are what people on the island truly hope for.

"By disregarding public safety and deceiving the people at will, Lai is bound to be rejected by the vast majority of Taiwan compatriots," he said.

Chen said the one-China principle represents the trend of the times and the shared aspiration of the international community, adding that Lai's so-called "diplomatic achievement" was nothing more than a political trick that would only draw ridicule. "The overarching trend toward national reunification is irreversible," he said.