United States Defence Secretary Chuck Hagel has acknowledged his government is no longer ruling out arming Syrian rebels.
It is the first time a senior American official has said openly that the US is reconsidering its opposition to supplying weapons to rebel forces.
Speaking in Washington on Thursday, Mr Hagel confirmed the US was reconsidering providing weapons to rebels, but stressed that no decision had been made yet, the BBC reports.
"Arming the rebels - that's an option. You look at and rethink all options. It doesn't mean you do or you will. These are options that must be considered with the international community: what is possible, what can help accomplish [our] objectives."
Mr Hagel made the comments at a joint news conference with British Defence Secretary Philip Hammond.
Mr Hammond said Britain had so far been unable to provide weapons due to a ban by the European Union on arming the rebels but "we will look at the situation when that ban expires in a few weeks' time".
In 2012, President Barack Obama rejected such a proposal in 2012, but now says the US was now looking at "all options".
During a visit to Mexico on Thursday he said the US was "continually evaluating the situation on the ground... to find the best way to move a political transition".
Meanwhile, allegations are emerging that Syrian forces carried out summary executions near the city of Banias.
The UK-based Syrian Observatory for Human Rights said it was trying to verify reports that troops had killed at least 50 people, including women and children, in the north-western village of al-Bayda.
The activist group monitors human rights violations on both sides of the conflict via a network of contacts across Syria.
Heavy fighting erupted on Thursday morning between government forces and rebels near the village.