The United Nations envoy on Syria, Staffan de Mistura, on Tuesday met Russian Foreign Minister Sergei Lavrov in Moscow as he looked to lay the groundwork for peace talks expected to resume next week.
The visit came as the UN said the talks will likely restart in Geneva on April 11, but that regime negotiators would only arrive several days later, after the completion of parliamentary elections in the country.
"I plan to go to other locations, Tehran, Damascus, Ankara, Riyadh, in order to prepare better, but it's really important to start here in Moscow," de Mistura said at the start of the meeting.
"Moscow has been instrumental to what can be seen as the real momentum in the political solution."
Russian forces intervened in Syria last year in support of long-time ally, President Bashar Al-Assad. Russia's support has helped Assad's regime make major advances, including recapturing the ancient city of Palmyra from Islamic State (ISIS) jihadists.
The last round of peace talks broke up on March 24, without making any concrete advances towards a political solution to the country's devastating five-year war.
Assad's fate remaining a major sticking point, with the opposition demanding he leave power – dead or alive – before any transitional government is agreed.
The regime says the president's future is not up for discussion.
Lavrov said it was very important to make sure that the opposing sides had "completed their homework" ahead of the next round of talks and reiterated calls for direct negotiations to start as soon as possible.
De Mistura has so far been leading indirect talks, meaning that the regime and opposition have so far not met face-to-face.
Before the previous round of talks was suspended, Assad's representatives said they would not return to Geneva until after the elections on April 13.
The UN does not recognize Syria's upcoming vote and is trying to strike a peace deal that would see fresh general elections, with opposition candidates included, held within 18 months.
AFP contributed to this report.