Talks between the United States, Russia, and regional players on how to end the Syrian conflict have ended in the Swiss city of Lausanne after more than four hours with no concrete action to stop the violence.

U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov were joined in Lausanne by UN Syria envoy Staffan de Mistura, along with the top diplomats of Turkey, Saudi Arabia, and Qatar -- all backers of Syrian opposition forces.

The talks were the first since Washington halted bilateral negotiations with Moscow following the collapse of a U.S.-Russia-brokered cease-fire deal last month.

Kerry said that new ideas were discussed for reviving the cease-fire, describing the meeting as a candid “brainstorming” session.

He said that despite tensions between the parties, they had agreed on the urgency of continuing to work together to restore the truce. He told reporters the next contact between sides at the talks would be on October 17 to discuss future steps.

The parties "might be able to shape some different approaches,” Kerry added.

Lavrov, who had previously said he had “no special expectations” for the meeting, told Russian media that the participants agreed to continue contacts in the near future and that they had discussed several “interesting ideas” and spoken in favor of launching a political process in Syria as soon as possible.

"We agreed that we must prolong our contacts over the coming days while taking into account certain accommodations that can help promote peace in Syria," Lavrov said at the end of the talks.

A senior U.S. official, traveling with Kerry, told reporters prior to the talks that the meeting was designed to explore ideas for ending the conflict, not to produce an immediate breakthrough.

Kerry and Lavrov began the talks with a 40-minute bilateral meeting, the first since October 3, when the U.S. suspended bilateral talks with Moscow on Syria, accusing Russia of failing to do its part to end the bloodshed.

Multilateral talks between the foreign ministers of Turkey, Saudi Arabia, and Qatar, which support the U.S.-backed rebels in Syria, took place right after. Iranian Foreign Minister Mohammad Javad Zarif was also present at the talks. Iran is a key supporter of Syrian President Bashar al-Assad's regime.

A Western diplomat in Lausanne told Reuters that the meeting appeared ill-prepared and vague in its goals.

“If it is to reach an agreement on Aleppo, countries have to make commitments -- Russia to stop bombing, Iran to withdraw its militia on the ground supporting Damascus,” the diplomat told Reuters as the talks were under way.

Kerry is scheduled to speak on October 16 about the process and the results of the Swiss talks with the foreign ministers of Britain, France, and Belgium.

The Syrian government launched an offensive to capture the eastern city of Aleppo three weeks ago. The United Nations says 275,000 civilians are still in the city and 8,000 rebels are opposing Syrian, Russian, and Iranian-backed forces.

Western powers have accused Russia and Syria of committing atrocities by bombing hospitals, killing civilians, and preventing medical evacuations.

Russia maintains that its air strikes on Aleppo have targeted militant groups holding parts of the city and accuses the United States of breaking the cease-fire by bombing Syrian troops fighting Islamic State militants.

The United Nations has said that Aleppo is running low on food, medicine, and fuel and that from the start of next month there will be no more rations to distribute.

With reporting by AFP, AP, dpa, and Reuters