Foreign Ministers of Russia and US held talks on Friday on the current crisis in Syria ahead of another meeting with the Saudi and Turkish FMs.

Foreign Ministers of Russia and US held talks on Friday on the current crisis in Syria ahead of another meeting with the Saudi and Turkish FMs.

Sergei Lavrov shook hands with John Kerry as they sat down a crunch meeting at a Vienna hotel. They will then see the duo joined by Saudi FM Adel al-Jubeir and Turkey's Feridun Sinirlioglu.

Washington, Riyadh and Ankara are looking to sound out Lavrov after the Syrian President made a surprise visit to Moscow to meet President Vladimir Putin this week.

The United States is leading a 60-plus member coalition allegedly targeting ISIL Takfiri group (so-called Islamic State in Iraq and Levant) in Iraq and Syria and has been carrying out frequent raids for more than a year.

Under the request of the Syrian government, Russia also is launching an air campaign against ISIL and other terrorists.

Earlier in Berlin, Kerry said that while all sides agreed on the need to find a political solution and battle IS only "one thing stands in the way... a person called Assad -- Bashar al-Assad".

However, analysts say some Assad opponents appear to be softening their line and conceding that he could remain in power temporarily, while Moscow does not seem wedded to the strongman long-term.