Former FBI Director James Comey will testify next Thursday before a US Senate panel investigating Russia’s alleged meddling in the 2016 US election, in a hearing that could add to difficulties facing President Donald Trump.

In his first public appearance since Trump fired him on May 9, Comey will address the Senate Intelligence Committee in both an open session and behind closed doors, which would allow him to discuss classified information, the committee says.

Comey was leading the FBI’s probe into the allegations, and his firing sparked a political uproar.

Facing rising pressure, the Justice Department last month named Robert Mueller, another former FBI chief, as a special counsel to investigate the matter.

The Justice Department and multiple US congressional committees are investigating Russia’s actions in the 2016 presidential election and questions about possible collusion between Russian officials and Trump campaign associates.

At next week’s hearing, Comey is expected to be asked about conversations in which Trump is reported to have pressured him to drop an investigation into former national security adviser Michael Flynn, whose ties to Russia are under scrutiny.