Moscow has revealed that it has information of at least 2,400 Russian nationals fighting for the Islamic State (isis) terrorist group in Syria and Iraq.

The First Deputy Director of Federal Security, Sergei Smirnov, said on Friday that of the 3,000 Central Asian nationals, at least 2,400 are Russians.

According to the RIA news agency report, Smirnov told journalists that the migrants' issue that is creating a crisis in Europe, poses a potentially "great threat" to Russia.

The statement from a senior Russian official comes days after TASS reported that more than 170 Russians have been killed in Syria fighting for Isis.

In 2014, the CIA had claimed that the Islamic State has 30,000 fighters drawn from over 80 countries. The Iraqi officials believe the number to be at least 2 lakh. 

The terrorist group, which now control almost 50% of Syria and Iraq, has radical fighters from France, UK, Germany, Morocco, Saudi Arabia, the United States, Canada and Russia, among other countries, in its ranks.

Russia recently proposed that the United States should include Kremlin and the Assad government to fight the Isis. It is believed that the US is still mulling over the proposal. 

In recent months, Russia has expanded its influence in Syria and been working on strengthening the Syrian forces in what is being termed a last-ditch effort to "save the Syrian ruler Bashar Assad".