US Secretary of State John Kerry warned today it will take years for a US-led coalition to defeat the Islamic State group, as Washington said arch-foe Iran had launched its first air strikes against the jihadists.
Kerry told the first high-level talks in Brussels of a coalition of around 60 nations that strikes in Iraq and Syria were having a "significant" impact and vowed that they would stay the course.
The Pentagon said Iranian F-4 Phantom jets hit IS fighters in eastern Iraq in recent days but denied any military coordination with long-term adversary Iran. Tehran refused to confirm or deny any strikes.
Iran is not a member of the coalition, but the claim suggested a tacit understanding between Iran and the United States to tackle the common threat from a group that proclaimed a caliphate in Iraq and Syria in June.
Kerry, opening the talks at NATO headquarters, told foreign ministers taking part that the coalition of western and Arab states "will engage in this campaign for as long as it takes to prevail".
"Our commitment will most likely be measured in years," he said.
But he added that "our efforts are already having a significant impact".
Kerry made no comment on Iran, while Iraqi Prime Minister Haider al-Abadi, asked about the Iranian action, said he had "no knowledge of any Iranian air strikes."
The United States launched its first strikes against IS in Iraq in August. In late September the strikes were extended to IS targets in Syria, involving the United States as well as a number of allies.
Saudi Arabia, the United Arab Emirates, Jordan and Bahrain are taking part in the air strikes in Syria. Australia, Belgium, Britain, Canada, Denmark, France and the Netherlands are participating in Iraq.
Dozens more countries are offering other support including information and intelligence sharing.
The United States has carried out the vast majority of the air strikes against the jihadists.
It says there are around 30,000 IS fighters in both Syria and Iraq, where the group is accused of atrocities including rape, crucifixion and the beheading of several westerners.
The Pentagon confirmed the Iranian strikes days after video emerged of what appeared to be an Iranian F-4 fighter -- looking like one of those acquired from the US before the 1979 revolution that toppled the country's pro-US shah -- attacking targets in Iraq's eastern province of Diyala.
