Chinese state media have accused Taiwanese President Tsai Ing-wen of using 'dirty tactics' for her election win

China on Sunday slammed officials from the US and other countries for congratulating Taiwan President Tsai Ing-wen after she was re-elected with a landslide victory in a stunning rebuke of Beijing's campaign to isolate the self-ruled island.

Tsai, who had pitched herself as a defender of liberal democratic values against an increasingly authoritarian China, secured a record-breaking win in Saturday's presidential election.

US Secretary of State Mike Pompeo, as well as top diplomats from Britain and Japan, issued statements congratulating Tsai and the island's democratic elections.

But Beijing, which views Taiwan as part of its territory, denounced their actions as violating the one-China principle.

"The Chinese side expresses strong dissatisfaction and resolute opposition to this," saidthe idea that Taiwan is part of "one China".

China doubled down on its "one-China principle" after Tsai's victory, with Geng emphasising Sunday that "regardless of what happens in Taiwan, the basic facts won't change: there is only one China in the world and Taiwan is part of China".

"The Chinese government's position won't change," he added in a statement.

-'Orchestrating tensions'-

Over the last four years, Beijing has ramped up economic, military and diplomatic pressure on the island, hoping it would scare voters into supporting Tsai's opposition.

But the strong-arm tactics have backfired and voters flocked to Tsai's DPP, fuelled in part by China's hardline response to months of huge and violent pro-democracy protests in Hong Kong.

Chinese state media have accused Tsai, who frequently invokes Hong Kong's protests as a warning about