FORMER US Secretary of State Mike Pompeo has been summoned by a Spanish court to explain an alleged CIA plot to assassinate Julian Assange in London. 

He has been asked to appear in connection with a probe into whether Spanish security firm UC Global spied on Mr Assange while providing security for the Ecuadorian embassy in London.

Spanish National High Court Judge Santiago Pedraz summoned Pompeo along with former US counterintelligence official William Evanina as witnesses in the case.