Beijing says US apologized after Trump's White House made 'Republic of China' gaffe
US President Donald Trump and Chinese President Xi Jinping (R) held talks at the G20 summit in Germany (AFP Photo/SAUL LOEB)

China said Monday the United States apologised after Beijing officially protested a White House statement that mistakenly described Xi Jinping as the president of the "Republic of China".

Xi is president of the People's Republic of China, while the Republic of China is the official name for Taiwan, which Beijing claims as a breakaway province awaiting reunification.

The error was made in an official readout of US President Trump's remarks before a bilateral meeting with Xi during last weekend's G20 summit in Hamburg, Germany.

It recalled Trump's initial wavering on the "One China" policy, which underpins relations between Washington and Beijing by acknowledging there is only one China and Taiwan is part of it.

Ties were also initially stymied by a protocol-busting phone call between the Beijing-sceptic president Taiwanese President Tsai Ing-wen and Trump following his election victory.

Then last month, the US administration further provoked the ire of Beijing when it approved $1.3 billion worth of arms sales to the self-ruling island.

America remains Taiwan's most powerful ally despite having no official relations with Taipei for decades.

"The US side has expressed that they are sorry for this technical error and they have made a correction," Chinese foreign ministry spokesman Geng Shuang said of the gaffe during a regular press briefing.

Tensions over Taiwan mark yet another drawback for Sino-US relations, which have turned tense as Trump has stepped up pressure on the Asian powerhouse to convince North Korea to abandon its nuclear programme.

In the last month, Washington has angered Beijing by imposing sanctions on a Chinese bank accused of laundering North Korean cash, voicing concern about freedom in semi-autonomous Hong Kong and sailing close to a disputed island in the South China Sea.

But Xi's title was not Washington's only flub last week: a separate news release called Japanese Prime Minister Shinzo Abe "President Abe of Japan."