The pair met in a Lausanne hotel shortly before they were to take part in a broader gathering with regional players to relaunch international efforts to end the Syrian war, officials said.
After talking for 40 minutes, Kerry and Lavrov joined envoys from Saudi Arabia, Turkey, Egypt, Iran, Jordan and Qatar to seek ideas on how to end the conflict.
Previously, Russia and the United States had pursued a joint effort to impose a ceasefire, but this broke down when Syria's Bashar al-Assad launched an assault on rebel-held east Aleppo.
Kerry has since accused Russian-led forces of taking part in the regime's bombing of hospitals and homes and has put an end to the bilateral track — while still remaining in close contact with Moscow.
Ahead of Saturday's talks, a senior US official travelling with Kerry told reporters that the plan was to bring the countries most deeply implicated in the conflict together to thrash out new ideas.
“The format through which we are pursuing solutions to this horrible conflict in Syria has evolved,” he said. “We are not pursuing this directly with the Russians bilaterally any more, but just because the format has evolved doesn't mean that the underlying objectives have changed.”
Those objectives, he said, are for a steep reduction in violence, increased humanitarian access to besieged civilian communities and eventually for a political dialogue between the government and opposition.