Breaking decades of US diplomatic policy, President-elect Donald Trump spoke to Taiwanese President Tsai Ing-wen and discussed various issues, a move which could infuriate China.
"President-elect Trump spoke with President Tsai Ing-wen of Taiwan, who offered her congratulations," the presidential transition team said on Friday in a readout of the phone call.
"During the discussion, they noted the close economic, political, and security ties existing between Taiwan and the United States," it said.
Trump's conversation with Taiwanese President on Friday was among a series of talks he had with the leaders of Asian countries on phone before taking office.
"President-elect Trump congratulated President Tsai on becoming President of Taiwan earlier this year," the readout said.
Trump also spoke with Afghanistan President Ashraf Ghani, who congratulated him on his historic victory.
"The two men discussed the grave terrorism threats faced by both the countries and pledged to work more closely together in order to meet these growing threats," the transition team said.
In another phone call, President of Philippines Rodrigo Roa Duterte offered congratulatory wishes to Trump. In their conversation, they noted the long history of friendship and cooperation between the two nations, and agreed they would continue to work closely on matters of shared interest and concerns.
Singapore Prime Minister Lee Hsien Loong also congratulated Trump on his remarkable election victory.
"The two men discussed the long history of good economic, political, and security relations between the United States and Singapore," the readout said.
The New York Times said the move by Trump is "a striking break with nearly four decades of diplomatic practice that could precipitate a major rift with China" even before Trump takes office.
He is believed to be the first President-elect or President to have spoken with a Taiwanese leader since 1979 when the US served its diplomatic ties with Taiwan after its recognition of China.
The Washington Post described this as a "breach of diplomatic protocol" with ramifications for Trump administration's relationship with China.
"The telephone call is certain to incense China, which considers Taiwan a renegade province. It is the first major sign of the unpredictability that Trump has vowed to bring to long-held US relations with the rest of the world," CNN said.