John Bolton has been called in to testify in the impeachment inquiry into US President Donald Trump.
The former National Security Adviser has been summoned by the House of Representatives investigators.
The US President is being investigated for pressuring Ukraine to investigate former US Vice-President Joe Biden and his son.
Trump denies the claims.
Bolton, who has spoken against the president on the matter, has been asked to testify on November 7.

US House blocks bid to impeach Defense Secretary Hegseth
Israel's parliament sworn in as Eisenkot tries to forge a government
Defiant Hegseth blasts impeachment effort ahead of House vote
Saudi official inspects Aramco Riyadh office after Houthi attack
