James Comey, FBI chief fired by Trump, due before Senate next week
Ex-FBI director James Comey will give evidence to the US Senate Intelligence Committee on 8 June as part of its investigation into Russian interference in last year's presidential election.
The committee is also looking into whether or not President Donald Trump's campaign team colluded in this.
Mr Comey was fired by President Trump last month.
He is expected to address reports that Mr Trump tried to get him to drop an FBI inquiry into Russian meddling.
However, there is speculation that the president might invoke executive privilege to prevent Mr Comey from testifying.
The committee said Mr Comey would testify in an open session at 10:00 local time (14:00 GMT), followed by a closed session.
He is likely to be asked about conversations with Mr Trump in which the president reportedly asked him to drop an investigation into former White House National Security Adviser Michael Flynn, who resigned when the details of his telephone conversations with the Russian ambassador to the US were made public.
The White House shocked Washington by announcing on 9 May that Mr Comey "has been terminated and removed from office".
The Trump administration said his handling of the inquiry into defeated Democratic presidential candidate Hillary Clinton's emails was the reason for his dismissal.
An FBI investigation into her use of a private email server to store sensitive information while secretary of state remains closed. Mr Comey said in July last year it was careless but not criminal.
But Trump critics said he was fired because the FBI was investigating the alleged links between the president's campaign and Russia.
It was only the second time the head of the FBI had been dismissed.
On 9 May, Mr Comey was addressing FBI agents in Los Angeles when, according to US media, he learned he had just been fired when he saw the news on television.
The 56-year-old - who was three and a half years into his 10-year term as FBI director - reportedly laughed, thinking it was a prank.