Kerry says any Iran strikes against IS 'positive'

The US secretary of state has said any Iranian action against the Islamic State group would be "positive", after Iranian officials were forced to deny US statements that their jets bombed IS positions in eastern Iraq.

John Kerry said on Wednesday evening: "If Iran is taking on IS in some particular place... and it has an impact, then it's going to be net effect that is positive."

He denied however that there had been any military coordination between Iran and the US.

His comments came after a meeting in Brussels of nations involved in the US's anti-IS coalition, its first since it launched its campaign against IS in Iraq and Syria.

Iran had earlier on Wednesday denied reports from the US defence department that its fighter jets were flying missions over Iraq.

"Iran has never been involved in any airstrikes against IS targets in Iraq," an unnamed Iranian official told Reuters on Wednesday. "Any cooperation in such strikes with the US is also out of the question."

The air raids, if proven, would have marked an escalation in Iran's role in a conflict in which Tehran and Washington have set aside customary hostility to battle a common enemy in the IS group.

"We have indications that they did indeed fly airstrikes with F4 Phantoms in the past several days," Pentagon spokesman Rear Admiral John Kirby told the AFP news agency.

His comments came days after al-Jazeera ran footage of what appeared to be an F4 fighter, similar to those used by the Iranian air force, attacking targets in Diyala.

We have indications that [Iran] did indeed fly air strikes with F4 Phantoms in the past several days. - Pentagon spokesman

Iranian forces have been active on the ground in Iraq assisting Shia militia and Baghdad government units, but this was the first time the United States had confirmed the Iranian air force was conducting strikes against the IS group.

No military coordination

Kirby said the United States was not coordinating with Iranian forces and that it was up to the Iraqi government to oversee military flights by different countries.

"We are flying missions over Iraq. We coordinate with the Iraqi government as we conduct those. It's up to the Iraqi government to deconflict that air space," Kirby told reporters.

"Nothing has changed about our policy of not coordinating military activity with the Iranians."

Even if there is no direct communication between the two countries' forces, the Americans would likely be aware and easily monitor flights over Iraq by Iran's less sophisticated air fleet, which uses a fighter jet that dates back to the Vietnam War.

A US air command centre in Qatar coordinates American fighters, 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 IS in Iraq has forged an unlikely alignment between Iran and the United States, which have been locked in a cold war for more than three decades.

The fight against IS 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.

But the two rivals remain deeply opposed over Syria, with Iran providing crucial military backing for President Bashar al-Assad, while Washington has vowed to train a moderate rebel force to eventually confront the Damascus regime.

Tactical communication

Analysts and former US officials say neither country appears ready to pursue elaborate cooperation for military operations in Iraq, but there appears to be some level of tactical communication at least to avoid accidents.

Nothing has changed about our policy of not coordinating military activity with the Iranians. - Pentagon spokesman

As the two governments expand their military activity in Iraq, there is a growing risk of potential crossed signals or conflict, as Washington and Tehran remain bitter enemies.

Shia-ruled Iran has close ties to the Shia-led government in Baghdad, and Tehran quickly came to the government's aid after Sunni militants overran Iraqi army units in western and northern Iraq earlier this year.

Iran also has provided Sukhoi Su25 aircraft to Iraq amid widespread speculation that the planes are flown by Iranian pilots.

Iranian weapons have reportedly made their way to Shia fighters in Iraq, including 12.7mm rifles designed to penetrate armoured vehicles and multiple rocket launchers, according to a report by IHS Jane's Defence.