Negotiations were to continue today, even as a dispirited President Barack Obama doubted the diplomacy would ever pay off.
Russia and the US have sought for weeks to secure a cease-fire between Syrian President Bashar Assad's government and moderate rebels that would expand access for hundreds of thousands of civilians caught in the crossfire.
The strategy has hinged on an unlikely US-Russian militarily partnership against extremist groups operating in Syria.
But beyond the Islamic State and al-Qaida, the two powers have conflicting views about who fits in that category.
"It's premature for us to say that there is a clear path forward, but there is the possibility at least for us to make some progress on that front."
A senior State Department official said the talks faltered yesterday when Russia pulled back from agreement on issues the US negotiators believed had been settled.
The official, who wasn't authorized to discuss negotiations publicly and requested anonymity, didn't elaborate. Kerry and Lavrov were consulting with their governments before talks resume on Monday.
Kerry and Lavrov's talks on the sidelines of the Group of 20 economic summit represent their third significant attempt since July to finalise a new US-Russian military partnership that Moscow has long sought.
The package would include provisions so aid can reach besieged areas of Syria and measures to prevent Assad's government from bombing areas where US-backed rebels are operating.
Disclaimer: No Business Standard Journalist was involved in creation of this content
