US Secretary of State John Kerry said President Bashar al-Assad is a "desperate leader" and praised the opposition as the legitimate voice of the Syrian people.
Mr Kerry confirmed the US will take "further steps" to help the opposition, which is faced by "brutal regimes" and Iranian forces.
He also added that the US will provide $60 million "immediately in non lethal assistance" to aid Syria opposition.
Secretary of State John Kerry said the US would provide the Syrian opposition with $60 million (about £39 million) in new aid and added that they would work with the rebel fighters.
At Rome #Syria meeting I said we cannot stand still while the crisis worsens and thousands of lives are at stake
From @WilliamJHague on Twitter:#Syria crisis needs a political solution. But for that to happen pressure on #Assad regime must rise
From @WilliamJHague on Twitter:UK urging peaceful resolution and UN Security Council action. But Syrians need urgent help, so will also be announcing new assistance
From @WilliamJHague on Twitter:
New US Secretary of State John Kerry has attended a gathering of nations in Rome who support the Syria opposition.
Foreign Secretary William Hague joined Mr Kerry as they met leaders of the Friends of Syria group.
Western and Arab governments have pledged more political and material support to the Syrian opposition, Reuters reports citing a statement released.
The Friends of Syria group deplored the "unabated" arms supply to President Bashar al-Assad's government by third countries.
