Petraeus  is expected to start his new job in September [Reuters]

The US Senate has voted unanimously to confirm General David Petraeus to be the new director of the Central Intelligence Agency (CIA).

Petraeus, commander of US forces in Afghanistan, was nominated by President Barack Obama to replace Leon Panetta, who is leaving the CIA to become the US secretary of defence.

Petraeus is expected to start his new job in September.

Before the vote on Thursday, the 58-year-old Petraeus was praised as "among the finest military officers and strategic thinkers of his generation," Dianne Feinstein, a Democrat and Senate Intelligence Committee chairwoman said.

The West Point graduate and 37-year army veteran is credited with turning around the war in Iraq, from where US troops have been withdrawing in large numbers, and in improving the security situation in Afghanistan.

Petraeus' challenges at the CIA will include providing accurate intelligence on trends in Afghanistan, tracking and neutralising armed groups on multiple continents, and tracking issues as diverse as climate change and the political effects of global economic upheaval.