Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State John Kerry have held twelve hours of talks in a bid to secure a military and humanitarian cooperation agreement for war-torn Syria.
After talks ended in Geneva on August 26 no major breakthrough, however, was announced.
Kerry said 'clarity' had been achieved with Russia on most steps to renew a truce in Syria.
He added narrow issues still needed to be resolved, something echoed later by Lavrov.
The talks in Switzerland were part of a new U.S. effort to enlist Russia as a partner in Syria as fighting becomes more volatile and complicated with the introduction of Turkish ground forces.
On August 25, UN officials said Russia was on board for a temporary pause in fighting in and around Aleppo.
However, the Russian Foreign Ministry simply reiterated its general support for a cease-fire to open an aid corridor, and was waiting for the UN to announce it is ready.
Lavrov and Kerry were also expected to discuss the conflict in eastern Ukraine, where fighting between Russia-backed separatists and forces loyal to Kyiv has flared up in recent weeks.