Donald Trump has spoken by telephone with Tsai Ing-wen, the president of Taiwan, risking a major diplomatic row with China.

Beijing firmly views Taiwan as part of a single Chinese nation.

The US and Taiwan have not had formal diplomatic relations since 1979, after the US had implemented a "One China" policy and closed its embassy in Taipei.

It is thought that no US president or president-elect has spoken with a leader of Taiwan since then.

The call was first reported by the Financial Times, and later confirmed by Mr Trump's transition team.

"President-elect Trump spoke with President Tsai Ing-wen of Taiwan, who offered her congratulations," according to a readout of the call released by Trump's transition team.

"During the discussion, they noted the close economic, political, and security ties exists between Taiwan and the United States. President-elect Trump also congratulated President Tsai on becoming President of Taiwan earlier this year."

Evan Medeiros, former Asia director at the White House national security council, said: “The Chinese leadership will see this as a highly provocative action, of historic proportions.

“Regardless if it was deliberate or accidental, this phone call will fundamentally change China’s perceptions of Trump’s strategic intentions for the negative. With this kind of move, Trump is setting a foundation of enduring mistrust and strategic competition for US-China relations.”

Earlier this week, Mr Trump risked angering India by apparently telling Nawaz Sharif, the Pakistani prime minister he would "love" to visit the country soon.

He described Pakistanis as "one of the most intelligent people", according to a Pakistani statement on the call.