US and Iranian officials are due to meet in Geneva on Thursday for a third round of indirect talks, as President Donald Trump threatens to strike Iran if a nuclear deal is not reached, BBC reported. 

The discussions come amid the largest US military build-up in the Middle East since the US-led invasion of Iraq in 2003, and with Iran vowing to respond to an attack with force.

The talks are seen as a last-ditch effort to prevent a conflict, but the chances of an agreement remain unclear, according to BBC.