President Barack Obama has said US forces will not fight another ground war in Iraq, a day after a top general said combat troops might be needed if efforts to defeat the Islamic State of Iraq and the Levant fail.

"I want to be clear. The American forces that have been deployed to Iraq do not and will not have a combat mission," Obama told troops at the US military's Central Command centre in Florida on Wednesday

His message came a day after General Martin Dempsey, chairman of the US Joint Chiefs of Staff, left the door slightly ajar to the possibility of some ground forces during congressional testimony.

"As your commander in chief I will not commit you and the rest of our armed forces to fighting another ground war in Iraq," Obama said.

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Iraq's new prime minister said earlier the same day that foreign ground troops were neither needed nor welcome on his country's soil.

In his first interview with foreign media since taking office on September 8, Haider al-Abbadi told the Associated Press news agency that US air strikes have helped Iraq's efforts to deter ISIL, but said foreign boots on the ground were "out of the question."

"Not only is it not necessary," he said, "We don't want them. We won't allow them. Full stop."

Dempsey had said that he might recommend having US troops do more, potentially accompanying Iraqis during complicated offensives, such as a battle to retake the northern city of Mosul from ISIL fighters.

"It could very well be part of that particular mission - to provide close combat advising or accompanying for that mission," he said.

Dempsey acknowledged that Obama's "stated policy is that we will not have US ground forces in direct combat.

"But he has told me as well to come back to him on a case-by-case basis".

Syria battle

Iraq's Abbadi, though ruling out ground troops, urged the international community to expand its campaign against ISIL to include neighbouring Syria.

"The fight will go on unless ISIL is hit in Syria," he said. "This is the responsibility of the international community - on top of them the United States government - to do something about ISIL in Syria." 

"We cannot afford to fight our neighbour, even if we disagree on many things," Abbadi said. "This is our neighbour. We don't want to enter into problems with them. For us sovereignty of Syria is very important."

ISIL was established in Iraq but spread to Syria, where years of civil war laid the ground for it to grow exponentially.

Following its success in Syria, the group's fighters - including many Iraqi nationals - took over northern and western Iraq in June, seizing control of a huge swath of territory. The group now rules over land stretching from northern Syria to the outskirts of Baghdad.

Source: Al Jazeera and agencies