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.
Some UK departing flights disrupted by NATS technical issue
Some departing flights at major British airports were disrupted on Tuesday after air traffic control provider NATS experienced a technical issue, with Heathrow, Gatwick, Manchester and Stansted among the airports affected by restrictions and delays.
At least 73 injured after Houthi rebels attack Saudi civilian and energy facilities
At least 73 civilians have been injured after Yemen's Houthi rebels attacked a number of civilian and energy facilities in Saudi Arabia's southern region on Tuesday, state media confirmed.
UK, France and Canada sanction Israeli West Bank settlements
Britain, France and Canada on Tuesday moved to block imports from Israeli settlements in the occupied West Bank, as a wider group of countries signalled further steps to defend the two-state solution amid mounting concern over settlement expansion.
Suspect detained after sabotage attacks on Germany power grid
German police have detained a 48-year-old man suspected of carrying out a series of sabotage attacks on the country's electricity grid, police and prosecutors said on Tuesday.
Nepal rescue focused on workers trapped in three tunnels
Rescuers in Nepal are focusing on three hydropower project tunnels where they believe dozens of workers could be trapped, authorities said on Tuesday, two weeks after a devastating flood killed hundreds and left thousands missing.
