Syrian officials say they are working to restore service to the Web after Internet connections went down Tuesday night, CNN reported.
The Syrian Arab News Agency said repairs would be done "as soon as possible."
Google said its services in Syria went down about 2:45 p.m. EDT Tuesday. Several other Internet tracking companies said they lost connections in Syria about the same time.
Opposition activists said the loss of the Internet could have ominous implications.
Dan Hubbard, chief technology officer for Umbrella Security Labs, said in a blog post that Syria had a history of Internet outages and that "past incidents were linked to both government-ordered shutdowns and damage to the infrastructure, which included fiber cuts and power outages."
InformationWeek reported outbound traffic resumed about 11 a.m. EDT Wednesday, about 24 hours after the outage began.
The United States and Russia called for Syria's regime and opposition to join urgent peace talks, with Washington saying the alternative was "chaos."
Kerry and Lavrov, who spoke at a midnight news conference in Moscow, said the international conference should be held "as soon as possible" and would seek to convince the Assad regime and the opposition to accept a six-point plan for a negotiated end to the conflict laid out in Geneva, Switzerland, 11 months ago.
The June 2012 plan, proposed by special joint U.N.-Arab League peace envoy Kofi Annan, called for a transitional government and is widely considered the most serious international attempt to resolve the Syrian civil war diplomatically.
Annan, whose peace plan was all but ignored by the warring parties, quit in August, saying he was frustrated by Syrian regime intransigence, an increasing rebel militancy and stubborn U.N. Security Council divisions that torpedoed his efforts.
"When the Syrian people desperately need action, there continues to be finger-pointing and name-calling in the Security Council," said Annan, who was the U.N. secretary-general from 1997-2006.
Kerry told the news conference Washington and Moscow believed "the Geneva communique is the important track to end the bloodshed in Syria." He called it a road map to a "new Syria."
He added the conference should take place "as soon as is practical -- possibly and hopefully by the end of the month."
"The alternative is that Syria heads closer to the abyss, if not over the abyss and into chaos," Kerry said, adding failure to reach a negotiated solution could mean the breakup of Syria, ethnic cleansing and wider instability in the Middle East.
Lavrov said, "We agreed that Russia and the United States will encourage both the Syria government and opposition groups to find a political solution."
Lavrov and Kerry didn't say where they envisioned the conference would convene or if they had confidence the meeting would actually take place.
The regime of President Bashar Assad and the Syrian National Coalition had no immediate response to the call for talks.
Kerry gave a softer version of the Obama administration's longstanding position Assad must be removed from power. He said he "personally" couldn't see how Assad could stay in power given the Syrian leader's misdeeds.
"But I'm not going to decide that tonight and I'm not going to decide that in the end," Kerry said.
He said the Syrian people would make that decision for themselves, hopefully under the Geneva guidelines, a position Moscow has advocated.
Lavrov left open the question of what happens to Assad.
"I would like to emphasize we are not interested in the fate of certain persons," Lavrov said. "We are interested in the fate of the total Syrian people."
Russia has long been one of the lone international powers propping up the Assad regime.