Joe Biden has made his first call for Donald Trump’s impeachment and told a rally the president has “already convicted himself”.
The former US vice-president is one of the Democratic front-runners in the 2020 presidential race.
His party has launched an impeachment inquiry over claims that Mr Trump illegally pressured a foreign leader to investigate Mr Biden and his son.
Mr Trump denies wrongdoing and has dismissed the probe as a “witch hunt”.
On Tuesday the White House said it would not co-operate, arguing that the proceedings were unconstitutional.
Addressing supporters in New Hampshire, Mr Biden said the president had already “violated his oath of office” and “indicted himself by obstructing justice, refusing to comply with a congressional inquiry”.
It was his most forceful response to date.
Previously, the former vice-president had only gone so far as to back an inquiry to gather the facts, even as his top Democratic rivals were calling for impeachment.
Shortly after Mr Biden spoke, Mr Trump hit back at “Sleepy Joe Biden” and his “failing campaign”.
Why is there an impeachment inquiry?
The Democratic-led inquiry is trying to establish whether the Republican president withheld nearly $400m (£327m) in aid to nudge Ukraine’s president into launching an…