The United States on Thursday pledged $60 million in "non-lethal" aid to rebels battling Syrian President Bashar al-Assad's regime after talks with the opposition in Rome.

In a grim reminder of the violence that has racked the country for two years, the announcement of aid came at the same time as news that a car bomb went off in a suburb of the flashpoint city of Homs, killing several people.

"The US will be providing an additional $60 million in non-lethal assistance to support the efforts of the Syrian opposition coalition over the coming months," new US Secretary of State Kerry said.

"We will be sending medical supplies and food to the (rebel) Supreme Military Council, so there will be direct assistance," he said, adding: "All Syrians... must know that they can have a future."

The announcement came after talks in Rome gathering the 11-nation Friends of Syria with the opposition at the 16th-century Villa Madama on a hilltop above Rome.

Kerry earlier met for about an hour with opposition leader Ahmed Moaz al-Khatib.

The US top diplomat had already said the opposition needs "more help" in the fight against Assad and that Washington wants to speed up the crisis-hit country's political transition.

The Rome talks come two days before an important meeting of the main opposition National Coalition on Saturday in Istanbul, where the umbrella group is to elect a prime minister and government to run parts of Syria seized from Assad's control.

On the ground in Syria, the state news agency SANA said "terrorists" set off a car bomb Thursday in the regime-controlled Akrama Jadideh suburb of Homs.

"Preliminary information indicates that there are dead and wounded," the agency reported.

Rebels also seized control of the Umayyad Mosque in the second city of Aleppo after days of fierce clashes that damaged the historic building, a watchdog reported.

Regime troops were forced to withdraw at dawn, taking up positions in buildings around the landmark structure, said the Syrian Observatory for Human Rights.

Momentum has been building ahead of Thursday's Rome talks, with the opposition -- which initially vowed a boycott -- lured back to the  meeting after the US and Britain promised specific offers of help.

Kerry, who was in Paris on Wednesday as part of a European tour, said in the French capital: "We are examining and developing ways to accelerate the political transition that the Syrian people seek and deserve."

He said he wanted to hear from opposition leader Khatib about how best to end the violence in Syria, where the United Nations says at least 70,000 have died and hundreds of thousands have been uprooted since the conflict broke out in March 2011.

"That may require us to change president Assad's current calculation. He needs to know he can't shoot his way out of this," Kerry said. "I think the opposition needs more help in order to be able to do that and we are working together to have a united position."

Kerry said there was a desire to help the opposition deliver assistance and basic services in areas it has "liberated from the regime".

US media including The New York Times and Washington Post have reported that the "non-lethal" aid could include equipment such as vehicles, communications gear and night-vision goggles.

The New York Times also reported that a US mission training rebels at a base in the region was already under way.

Pressure has been building for talks on ending the crisis, with Russia, Assad's most powerful supporter, this week urging both sides to sit down for negotiations.

In Moscow, French President Francois Hollande said ahead of a meeting with Russian counterpart Vladimir Putin that a political solution to the Syrian crisis was possible within weeks.

"I think that in the next few weeks we will manage to find a political solution that will stop the conflict from escalating," Hollande told Echo of Moscow radio station in comments translated into Russian.

Hollande stressed Russia's key role as a member of the UN Security Council, where it has vetoed resolutions that would have put pressure on Assad to end hostilities.

"We must finally start the process of political dialogue that has not yet started on the territory of Syria."

"President Putin and I both understand all the seriousness of the situation. And even though our positions at the moment differ, we want to find the best solution for Syria."

Officials from the United States, Britain, France, Germany, Italy, Turkey, Egypt, Jordan, Saudi Arabia and the United Arab Emirates took part in the talks in Rome, as well as EU foreign policy chief Catherine Ashton. (AFP)