Saudi Arabia and other Gulf Arab states are discussing sending special forces to Syria as part of U.S.-led efforts to fight Islamic State militant group, Foreign Minister Adel al-Jubeir said on Tuesday.

"There are discussions, countries that are currently part of the coalition (like) Saudi Arabia, the (United Arab) Emirates, Qatar and Bahrain about sending in some special forces into Syria, and those discussions are ongoing. It's not excluded," Adel al-Jubeir told reporters.

He said that the discussions were aimed at clarifying the needs and the objectives of such an operation, but that the picture should become clearer in the next few weeks.

Jubeir was speaking in Paris after outlining a separate initiative by Riyadh to set up a coalition of Islamic countries for counter-terrorism operations, especially in Iraq, Syria, Libya, Egypt and Afghanistan.

The United States has already sent special forces to Syria to help rebels coordinate efforts against Islamic State and has discussed the issue with other members of the coalition, including France.

While Saudi Arabia and other Gulf Arab states are part of the same coalition, they have carried out limited air strikes in Syria. Most of their effort has gone towards arming opposition groups and backing efforts to oust President Bashar al-Assad.

"Assad's position is not tenable. He will not be saved and the war is not winnable for him," Jubeir said.

Saudi Arabia has been working over the last week to bring the Syrian opposition together before possible talks with the Syrian government in January. Jubeir said a genuine opposition now existed and Syria's government had no reason not to negotiate.

"Now we have a serious opposition, nobody can say there isn't one," he said. "It doesn't stand for Daesh and we have negotiators willing to sit at the table. If the other side is serious - Assad and his allies - then show me the team and let's see how we can work on transition of power and a ceasefire," he said.

He urged Russia to exert its influence on the Syrian government.

U.S. Secretary of State John Kerry is in Moscow to discuss with Putin and Foreign Minister Sergei Lavrov preparing the ground for a third round of talks of world powers on Syria, pencilled in for Friday in New York.

It is unclear whether the meeting will go ahead without progress between Russia and the United States over the role of Assad in any political transition and over which rebel groups should be part of peace talks.