Air strikes carried out by the US-led collation on Islamic State (IS) have inflicted “significant” damage on the group’s capabilities, US Secretary of State John Kerry says.
Mr Kerry said the campaign against the militant group could take years, but that the coalition would remain engaged “as long as it takes”.
The US said earlier that Iran, not a coalition member, had carried out air strikes against IS in Iraq.
However, Iran has denied this.
The US said there had been no coordination with the Iranians on any air strikes.
IS controls large areas of Syria and Iraq, imposing a rigid version of Sunni Islam and persecuting or killing non-believers.
The reported Iranian air strikes against Islamic State targets in Iraq underscore that while Iran and the US are not exactly on the same side in this struggle (due not least to the Iranians’ support for President Bashar al-Assad in Syria) they do at least share the same enemy in IS.
Iran is of course a long-standing ally of Iraq’s Shia-dominated government and was the first country to offer military support for its campaign against IS. Earlier this year Iran provided a number of SU-25 Frogfoot combat aircraft to Iraq which may well be crewed by Iranian pilots.
Iran has also provided high-level military expertise and there have been unconfirmed reports of Iranian armour being involved in fighting on the ground. Washington and Tehran have certainly had discussions about the common IS threat but it is far from clear how much, if any, actual coordination there has been between them.
Mr Kerry was speaking at a meeting in Brussels of officials from all of the nations involved in the coalition.
“Our commitment will be measured most likely in years but our efforts are already having a significant impact,” he said.
Two months of air strikes had “reduced Daesh’s [IS] leadership and inflicted damage on its logistical and operational capabilities”.
Thanks to coalition action, he said, it had become much harder for IS to “assemble forces and strength, to travel in convoys and to launch concerted attacks”.
“No large Daesh unit can move forward aggressively without worrying about what will come down on it from the sky,” Mr Kerry said.
According to a list compiled by the US state department, at least 62 countries are members of the coalition, although most play no direct role in the air strikes.