Iran has denied it conducted air strikes against ISIL targets in eastern Iraq, after Al Jazeera ran footage of what appeared to be an F-4 fighter jet, similar to those used by the Iranian air force.

Speaking on condition of anonymity, an Iranian official told Reuters news agency on Wednesday that "Iran has never been involved in any air strikes against the Daesh targets in Iraq."

The official was using the Arabic acronym for the Islamic State of Iraq and the Levant (ISIL), the armed group which controls large expanses in Iraq and Syria.

"Any cooperation in such strikes with America is also out of question for Iran," the official said.

The Al Jazeera footage of the alleged F-4 fighter was filmed on November 24 as the jet struck ISIL targets in the province of Diyala, prompting media reports that Iran was involved in the US-led coalition against ISIL.

The Pentagon on Tuesday said it had no reason to doubt reports that Iranian fighter jets had bombed ISIL targets in Diyala.

"I have seen those reports. We have no indication that the reports are not true that Iranian aircraft have conducted air strikes, in the last several days, against ISIL targets in eastern Iraq," John Kirby, the Pentagon press secretary, said.

"Again, you should consult the Iranian government to speak to the activities of their government."

Israeli media suggested it was highly unlikely that Iranian fighter jets would be operating in the same area as the international coalition without significant coordination.

However, the deputy chief of staff of the Iranian armed forces has dismissed those reports as "totally untrue".

"The Islamic Republic of Iran blames the United States as the root cause of unrest and problems as well as the terrorist actions of ISIL in Iraq," Iran's state news agency FARS quoted General Massoud Jazayeri, as saying.

On his part, Kirby also said that "nothing has changed about [US] policy of not coordinating military activity with the Iranians".

'Iranian F-4 Phantom'

Jane's Defence Weekly identified the aircraft shown in the Al Jazeera footage as an "Iranian McDonnell Douglas F-4 Phantom II jet".

"Iran and Turkey are the only regional operators of the F-4, and the location of the incident not far from the Iranian border, and Turkey's unwillingness to get involved in the conflict militarily, indicate this to be an Islamic Republic of Iran Air Force [IRIAF] aircraft," Jane's Defence Weekly wrote.

A US air command centre in Qatar coordinates American fighter jets, bombers, drones and surveillance aircraft flying round-the-clock missions over Iraq along with other coalition warplanes from European governments as well as Australia and Canada.

The onslaught of ISIL in Iraq has forged an unlikely alignment between Iran and the US, which have been locked in a cold war for more than three decades.

The fight against the ISIL has come amid a US diplomatic drive to agree a deal with Iran over its nuclear programme, and officials acknowledge the two sides have discussed the war in Iraq on the margins of the nuclear talks.

However, the US and Iran remain deeply opposed over Syria, with Iran providing crucial military backing for President Bashar al-Assad while the US has pledged to train a moderate rebel force to eventually confront the Assad government.

The Iranian denial of involvement in air raids in Iraq came as John Kerry, US secretary of state, hosted a meeting in Brussels of ministers from the 60 members of the US-led anti-ISIL coalition.

Military strategy topped the agenda of Wednesday's meeting in the Belgian capital but the delegates would also discuss how to stop the flow of foreign fighters joining ISIL.