Lawmakers are trying to obtain testimony from informer, but are concerned about safety after US president calls actions treasonous

Senior State Department official says US secretary of state was 'among administration officials' on July 25 call; Democrats subpoena Giuliani to turn over Ukraine-related documents

US president lashes out as Democratic-led House moves ahead with its inquiry into abuse of power; civil war tweet draws condemnation from Republican lawmaker

New report claims president told Russian FM he was unconcerned about Moscow's interference in 2016 election as US did the same in other countries

White House allegedly tried to cover up details of president's phone call; intelligence chief Joseph Maguire calls whistleblower complaint 'unprecedented' amid impeachment calls

'I didn't do it, I didn't threaten anybody. No push, no pressure, nothing,' US president tells reporters a day after Democrats announce the launch of proceedings against him

US president reportedly turned to Ukrainian leader Volodymyr Zelensky in bid to piece together a corruption complaint against Joe Biden ahead of 2020 race

Volodymyr Zelensky, a Jewish comedian who won a landslide victory in elections, dissolves parliament, urges ministers to resign and vows to solve Donbas crisis

Though he won election, 41-year-old does not have a parliamentary majority, faces challenges of separatist conflict and ongoing economic problems

Zelensky, also a comedian, joked about his Jewish roots during an election campaign lauded for absence of anti-Semitism