The US House of Representatives is preparing to vote to possibly impeach President Donald Trump.
Mr Trump is accused of pressuring Ukraine to dig up damaging information on one of his main Democratic challengers for the presidency in 2020, Joe Biden, and his son Hunter.
A formal complaint from a whistleblower – an unnamed intelligence official who wrote a letter expressing concern about Mr Trump’s 25 July call with President Volodymyr Zelensky – kicked off the impeachment process in early September.
A rough transcript of the call revealed that Mr Trump had urged President Zelensky to investigate discredited allegations against Joe and Hunter Biden.
President Trump, who is a Republican, strongly denies any wrongdoing.
Video by Tristan Cimini and Shrai Popat