Washington: The White House and the US military on Tuesday scrambled to play down a suggestion by the nation’s top officer that deploying ground forces in Iraq to fight Isil militants was an option.

General Martin Dempsey, chairman of the US Joint Chiefs of Staff and President Barack Obama’s top military adviser, had said US military advisers could be sent into combat alongside Iraqi forces.

Dempsey said the US personnel could “provide close-combat advising,” but the White House insisted the idea of US troops in battle was a “purely hypothetical scenario.”

And in a day of mixed messages, Colonel Ed Thomas, a spokesman for the general, then tried to bring some clarity to the situation, saying in a rare statement that Dempsey “doesn’t believe there is a military requirement for our advisers to accompany Iraqi forces into combat.”

Military leaders nevertheless warned of a further escalation in their battle against the militants, just as two branches of the rival Al Qaida group called for a united front against the war coalition Washington is building.

US jets have been targeting Isil fighters in northern Iraq since August 8, and in recent days hit militants southwest of Baghdad for the first time, in a significant expansion of the campaign.

US Central Command said that, in addition to bombing Isil fighters threatening the northern city of Arbil, strikes had destroyed a guerrilla ground unit and two supply boats southwest of Baghdad.

The campaign appeared to bear fruit on Tuesday when Kurdish peshmerga fighters — who now receive Western military supplies and US air support — retook seven Christian villages overrun by militants.

In Washington, Defence Secretary Chuck Hagel told US lawmakers that plans were being laid to hit targets in Syria, where the Isil group is holding Western hostages and has a stronghold in the city of Raqqa.

“This plan includes targeted actions against Isil safe havens in Syria, including its command and control, logistics capabilities, and infrastructure,” Hagel told the Senate Armed Services Committee.

Dempsey had gone further than any US official before in saying that the military advisers that Obama has dispatched to bolster Iraqi forces could get drawn into combat.

‘Mission creep’

Obama’s administration has insisted that his action against the Isil extremists is not the start of another US ground war in the Middle East, and that there will be no large-scale American invasion.

But nearly 300 US military advisers are already working with Iraqi government forces, 300 more are on their way and Dempsey refused to rule out them providing “close-combat advising.”

White House spokesman Josh Earnest was keen to underscore this, after Dempsey’s remarks caused a flurry of speculation that US forces would once again suffer “mission creep” in the Middle East.

Earnest said Dempsey “was referring to a hypothetical scenario in which there might be a future situation in which he might make a tactical recommendation to the president as it relates to the use of ground troops.”

“The president has been clear about what that policy is: the president does not believe that it would be in the best interest of our national security to deploy American ground troops in a combat role in Iraq and Syria. That policy has not changed.”