Mitt Romney
Mitt Romney to cite Iran's role in Syria to back his call for arming the rebels. Reuters

US presidential challenger Mitt Romney is to call for arming the Syrian rebels in the ongoing uprising against President Bashar al-Assad.

During his foreign policy speech in Lexington, Virginia, the Republican candidate will pledge to "work with our partners to identify and organise those members of the opposition who share our values and ensure they obtain the arms they need to defeat Assad's tanks, helicopters, and fighter jets" if he is elected.

Although he has openly supported Syrian rebels, who have been locked in battle with Assad's troops for the last 18 months, Romney has never previously called for arming them.

The incumbent Obama administration has thus far been opposed to both military intervention and arming the rebels, even after open requests from Syrian opposition groups. Washington has instead been providing non-lethal aid to the rebels, while pressuring Saudi Arabia and Qatar to stop supplying arms to the opposition groups.

Romney's speech will call for a major shift in American foreign policy. The former Governor of Massachusetts will tell his audience that "Iran is sending arms to Assad because they know his downfall would be a strategic defeat for them. We should be working no less vigorously with our international partners to support the many Syrians who would deliver that defeat to Iran - rather than sitting on the sidelines."

Romney, who is widely thought to have won the first televised debate against Obama, is also expected to attack the President's administration over the handling of the Benghazi attack in Libya which killed the US ambassador. He will say:

"The attack on our consulate in Benghazi on September 11th, 2012 was likely the work of the same forces that attacked our homeland on September 11th, 2001. This latest assault cannot be blamed on a reprehensible video insulting Islam, despite the administration's attempts to convince us of that for so long."

The Obama campaign is reportedly preparing to counter Romney by once again focusing on his gaffes and poor track record on foreign policy remarks.