Iraqi Prime Minister Haider al-Abadi said in a TV interview aired on Thursday that he would consider allowing Russia to carry out airstrikes on Islamic State militants in Iraqi territory if Moscow offered.

With Russia already bombing what it says are "terrorist" positions in Syria, Abadi told France 24 in an interview recorded on Wednesday: "It is a possibility. If we get the offer, we will consider it."

The interview was done a day before senior Russian foreign ministry official Ilya Rogachyov on Thursday said Moscow was prepared to consider expanding its military campaign beyond Syria to launch strikes against IS targets in Iraq, if Baghdad asked it to do so.

But Russian officials appeared to be giving mixed signals, with Foreign Minister Sergei Lavrov saying shortly afterwards that no expansion to Iraq was planned.

"We are not planning to expand our airstrikes to Iraq," Lavrov told a news conference at the United Nations in New York. "We were not invited, we were not asked, and we are polite people, as you know. We don't come if not invited."

"Syria has massive information on Daesh (another term for the Islamic State group), and their operations," said Abadi.

"They are sharing, it is useful. Russia seems to have a lot of information too. The more information we gather, the more it is useful for Iraq."