Meeting Mr Hagel in Baghdad, Prime Minister Haider al-Abadi said Iraqi forces were advancing against Islamic State, which has seized large parts of the country.

“But they need more air power and more ... heavy weaponry. We need that,” Mr Abadi told Mr Hagel, who was on probably his last visit to the Iraqi capital as ­Pentagon chief.

His request highlighted a ­disagreement over war strategy between Baghdad and Washington, with the Americans favouring a more limited air campaign until Iraqi forces are ready to hold on to territory and organise major ­offensives.

“The focus of our conversations today was the effort to degrade and defeat ISIL, and as I discussed with Iraqi leaders, we are seeing steady progress in achieving this objective,” Mr Hagel said.

He said he appreciated Mr Abadi’s “directness” in requesting more firepower and added: “We talked about how in fact ... the US has accelerated weapons systems that Iraq will need” such as Hellfire air-to-surface missiles and other arms and ammunition.

Mr Hagel, speaking to a group of US and Australian troops, said the outcome of the campaign would ultimately hinge on the Baghdad government.

Mr Hagel announced his resignation last month. President ­Barack Obama on Saturday nominated former defence deputy ­secretary Ashton Carter to replace him.

AFP