KIEV: Ukraine's President Volodymyr Zelensky on Thursday hailed the confirmation of Joe Biden as the next US president despite a "horrific attack" by supporters of Donald Trump, who in 2019 was accused of attempting to coerce Kiev into discrediting his rival.

"We strongly condemn the unprecedented violence against the US Congress," Zelensky said in a tweet after US lawmakers confirmed Biden a day after mobs of Trump supporters stormed the US Capitol.

"We are inspired by the resilience of this world's oldest & greatest democratic institution that within mere hours of this horrific attack held a historic session that affirmed the will of the American people".

Former comedian Zelensky became the central figure of a US political scandal months after winning the Ukrainian presidential election in the spring of 2019.

A whistleblower report revealed a phone call between Trump and Zelensky in which the US president tried to coerce Ukraine into launching an investigation into Biden, whose son used to be a board member of a Ukrainian gas company.

Trump is said to have threatened to withhold nearly $400 million in military aid to Kiev, which is battling pro-Russian separatists in eastern Ukraine.

The events led to the launch of an impeachment process against Trump but the president was acquitted by the majority-Republican Senate.