US Secretary of State John Kerry said today supporters of Syria's rebels will step up military and other aid in a bid to end an "imbalance" in President Bashar al-Assad's favour.
On the ground, loyalist forces pressed a fierce four-day assault on rebel-held parts of Damascus, while insurgents launched a new attack on regime-controlled neighbourhoods of second city Aleppo.
Kerry, speaking at a "Friends of Syria" conference of foreign ministers in Qatar, said Washington remained committed to a peace plan that includes a conference in Geneva and a transitional government picked both by Assad and the opposition.
He said the United States supported the original Geneva Communique as it sets up a process by under which transitional government would be "put in place to end the conflict" and "chosen by mutual consent of both the Assad regime as well as the opposition".
The rebels need more support "for the purpose of being able to get to Geneva and to be able to address the imbalance on the ground," Kerry said.
"Reliable civilian governance and a stronger and more effective armed opposition will better enable the opposition to be able to provide the counterweight to the initiative of Assad," he said.
To that end, he said, "the United States and other countries here -- in their various ways, each choosing its own approach -- will increase the scope and scale of assistance to the political and military opposition."
Kerry said governments at the conference -- including those of stalwart rebel supporters Qatar and Saudi Arabia -- would work to "coordinate our support" to the opposition's Supreme Military Council.
US President Barack Obama has announced plans to step up assistance to the rebels after concluding that Assad crossed his stated red line by using chemical weapons.
But the United States has said little about its own assistance, with Obama voicing concern about becoming too involved in the increasingly sectarian conflict.
Qatari Prime Minister Sheikh Hamad bin Jassem al-Thani echoed Kerry's remarks, calling for arms deliveries to the rebels to create a military balance that could help forge peace.
A peaceful end "cannot be reached unless a balance on the ground is achieved, in order to force the regime to sit down to talks," he told the ministers.
"Getting arms and using them could be the only way to achieve peace."
British Foreign Secretary William Hague said London had taken "no decision" to arm the rebels.
