WASHINGTON - Iran has conducted air strikes against Islamic State (IS) targets in eastern Iraq during recent days, a Pentagon spokesman said, reflecting tacit Washington-Tehran cooperation to combat the terrorist group which controls vast stretches of Iraqi and Syrian territory.

But Spokesman Rear Admoral John Kirby insisted  the US, which has conducted its own air strikes in Iraq, was not co-ordinating with Iran. A senior Iranian military official also dismissed talk of co-operation between the two countries, according to press reports. A US-led coalition has launched hundreds of air strikes against IS since August.  The United States has said it would be inappropriate for Iran to join that coalition, even though the two long-time adversaries face a common enemy in IS.  Since the Islamic revolution in 1979, the US and Iran have had a fraught relationship. Washington severed ties the following year after Iranian students occupied the US embassy in Tehran and took 52 Americans hostage.

Rear Adm Kirby’s comments followed reports that American-made F4 Phantom jets from the Iranian air force had been targeting IS positions in the eastern Iraqi province of Diyala.  “We have indications that they did indeed fly air strikes with F-4 Phantoms in the past several days,” he said. It was up to Iraq to oversee and co-ordinate flights by different countries in its airspace, he added.  “We are flying missions over Iraq, we co-ordinate with the Iraqi government as we conduct those,” he said. “It’s up to the Iraqi government to deconflict that airspace.”  “Nothing has changed about our policy of not co-ordinating military activity with the Iranians,” Kirby added.

AFP adds: Secretary of State John Kerry hosting on Wednesday a meeting of the US-led coalition against the militant group. The Pentagon said Iranian jets hit IS militants in eastern Iraq in recent days. The information suggested a tacit understanding between archfoes Iran and the United States to tackle the common threat, though both deny any military coordination.

Iran was not at the meeting hosted by Kerry at NATO’s headquarters in Brussels because it is not part of the US-led grouping.

Kerry, opening the talks, told the 62 foreign ministers taking part that the coalition “will engage in this campaign for as long as it takes to prevail”. “Our commitment will most likely be measured in years,” he added.

Kerry made no immediate comment on the Iranian air strikes. But Iraqi Prime Minister Haider al-Abadi, asked about the Iranian action, told journalists: “I have no knowledge of any Iranian air strikes.”

Kerry said IS represented a danger to the interests and values of all thoses attending, including European, Arab and Asian countries. Officials said the coalition would also look at how to stem the flow of foreign fighters and counter the powerful IS “brand” that has drawn militants from several Western countries, partly through the use of social media.

“As we are able to delegitimise (IS) we are able to turn populations against (IS), reduce their recruiting basis,” a US official told AFP. They will also study ways to disrupt how IS raises finances through oil sales, extortion, plunder, ransom, human trafficking and the sale of Syrian antiquities, he said. Coalition partners are to meet again in the Moroccan city of Marrakesh on December 15 to further tackle the foreign fighters problem.

NATO allowed its headquarters to be used for Tuesday’s talks because foreign ministers from the transatlantic alliance met there on Tuesday, but NATO is not part of the US-led coalition against IS.

Reuters adds: Syrian President Bashar al-Assad said US-led strikes in Syria have made no difference and described himself as a captain trying to save his ship, in comments to a French magazine and carried by the presidency’s Twitter feed on Wednesday.

Coalition forces led by the United States began bombing Islamic State militants and other militant factions in Syria in September. Asked whether this had been helpful to him, Assad, whose forces have fought the same groups, told Paris Match: “You can’t end terrorism with aerial strikes.

“Troops on the ground that know the land and can react are essential. That is why there haven’t been any tangible results in the two months of strikes led by the coalition,” he said according to interview extracts on Paris Match’s website in English.

“It isn’t true that the strikes are helpful. They would of course have helped had they been serious and efficient. We are running the ground battles against Daesh (Arab acronym for Islamic State), and we have noticed no change, especially with Turkey providing direct support to these regions.”

Turkey denies Syrian accusations that it backs Islamist insurgents like Islamic State in Syria.

US Secretary of State John Kerry said on Wednesday the aerial campaign had inflicted serious damage on Islamic State but the fight could take years.

Asked whether he feared the same demise as the late rulers of Iraq and Libya, Assad replied: “The captain doesn’t think about death, or life, he thinks about saving his ship.

“If he thinks about sinking, everyone will die. I am doing my best to save the country,” he said in the interview conducted on Friday in Damascus.