BAGHDAD — Iraq will begin sharing "security and intelligence" information with Russia, Syria and Iran to help combat the advances of the Islamic State group, the Iraqi military announced Sunday.

A statement issued by the Iraqi Joint Operations Command said the countries will "help and cooperate in collecting information about the terrorist Daesh group," using the Arabic acronym for the Islamic State group.

Iraq has long had close ties with neighboring Iran and has coordinated with Tehran in fighting the advance of IS — which controls about a third of Iraq and Syria in a self-declared caliphate. Iranian commanders have helped lead Iraqi Shiite militiamen in combat.

A U.S.-led coalition has been conducting aerial bombing campaigns against IS positions in Iraq and Syria, but U.S. officials insist they have no coordination with Tehran on the matter.

The agreement with Russia comes at a time when Moscow is ramping up its involvement in Syria in defense of its ally Bashar Assad, with Russian soldiers on the ground in Syria, according to activists. The Iraqi military statement said that Moscow is increasingly concerned about "the presence of thousands of terrorists from Russia who are carrying out criminal acts with Daesh."