Syrian rebels said Friday that newly arrived shipments of heavy weaponry could swing the momentum on the battlefield in their favor, after a shift in U.S. policy opened the door for others to send them arms.

Weapons from the United States have not materialized since the White House announced the previous week that it had authorized direct military support for the opposition, but the U.S. decision appears to have prompted other nations to boost their assistance, with new deliveries including highly prized anti-tank and anti-aircraft weaponry, said Khalid Saleh, a spokesman for the main Syrian Opposition Coalition.

Saleh declined to provide specifics but said shipments had come from countries in the Friends of Syria Group, a coalition of 11 Western and Arab nations that back the opposition. The group was due to meet in the Qatari capital, Doha, on Saturday to discuss coordinating military support for the rebels.