Russian Foreign Minister Sergei Lavrov said Wednesday that the Islamic State group was Moscow's greatest enemy, notwithstanding the strained relations with the United States over the Ukraine conflict.

"I believe IS is our greatest enemy right now," Lavrov said in an interview with Russian radio stations when asked whether he considers China, IS or NATO Russia's greatest threat.

Lavrov said "hundreds of Russian citizens, hundreds of Europeans, hundreds of Americans are fighting for IS, along with CIS (former Soviet) countries."

"They are already returning home. They come here to rest after fighting and can get up to dirty tricks at home," he said.

"As far as (relations with the) United States are concerned, these are state issues, these are issues of the world order, which have to be resolved through talks."

Russia's relations with the West, particularly with the United States, have plummeted to a post-Cold War low over the war in Ukraine and sanctions imposed over Moscow's role in supporting pro-Russian militants.

IS 'virus' seeks to destroy Muslim world: Erdogan
Ankara (AFP) April 22, 2015 - Turkish President Recep Tayyip Erdogan on Wednesday launched one of his strongest attacks yet against Islamic State (IS) jihadists, saying the group was a "virus" working to destroy the Muslim community.

Ankara has been repeatedly criticised in recent months for not doing enough to halt the advance of IS to its borders, but Erdogan said after meeting Iraqi President Fuad Masum that the group had to be confronted.

The IS group "is an important virus that is working to divide and destroy the ummah", Erdogan told reporters in televised comments, using the term for the community of Muslims.

He said other groups had followed the same path but that IS had proved more adept and serious in using its resources.

"An international strategy is essential to drain this swamp. Even if Daesh is destroyed something will emerge under a different name," said Erdogan, using a pejorative Arabic acronym to refer to IS.

"Where do its weapons and financing come from? We need to focus on this," Erdogan said.

Turkey had itself been accused of aiding IS in the early stages of its existence as a useful ally in the fight against Syrian President Bashar al-Assad, who Erdogan wants to see ousted.

But Ankara has vehemently denied the charges.