Rebels to meet UN Security Council
Jarba and three other senior SNC members - Burhan Ghalioun, Najib Ghadbian and Michel Kilo - are in New York to meet informally with the 15-member UN Security Council on Friday.
Jarba and rebel military commander General Salim Idriss met with French President Francois Hollande and other French officials in Paris earlier this week to appeal for diplomatic, humanitarian and military aid.
The Syrian rebels are frustrated that US plans to send weapons to them have been held up by congressional concerns.
Saudi Arabia, Qatar and Turkey have been supplying the rebels with arms, security sources and diplomats say.
"Military and violent actions must be stopped by both parties, and it is thus imperative to have a peace conference in Geneva as soon as possible," UN Secretary-General Ban Ki-moon said after meeting with Kerry on Thursday.
The United States, Russia and the United Nations are still working to convene a meeting in Geneva between the Syrian government and opposition groups to try to broker a peace deal.
So far, attempts to organize a so-called "Geneva II" peace conference on Syria to revive a political transition plan agreed in the Swiss city in June 2012 have been futile. UN diplomats say it is looking increasingly unlikely that such a conference will take place anytime soon, if at all.
Kerry told reporters that his almost hour-long meeting with the Syrian opposition leaders had been "constructive."
"The Syrian opposition committed that they believed Geneva II is very important and they agreed to work over the course of the next couple of weeks to pinpoint the terms, the conditions under which they think it could work," he said.