Beijing has lodged a protest with the United States over a call between US President-elect Donald Trump and Taiwanese leader Tsai Ing-wen, the foreign ministry said Saturday.

"We have already made solemn representations about it to the relevant US side. It must be pointed out that there is only one China in the world. Taiwan is an inalienable part of China's territory," the statement said.

"We urge the relevant parties in the US to abide by the commitment to the one-China policy" and "to handle Taiwan-related issues with caution and care to avoid unnecessarily interfering with the overall situation of Sino-US relations," it said.

Mr Trump's telephone call with Ms Tsai broke with decades of foreign policy and fuelled fears he is improvising on international affairs.

'Just a small trick'

Earlier, China's foreign minister, Wang Yi, downplayed the significance of the call between Taiwan's president and Mr Trump, saying it was "just a small trick by Taiwan" that he believed would not change US policy toward China, according to Hong Kong's Phoenix TV.

"The one-China policy is the cornerstone of the healthy development of China-US relations and we hope this political foundation will not be interfered with or damaged," Mr Wang was quoted as saying.