Senior US officials have said they are considering an Iraqi request for more American military advisers to help Iraqi security forces in their campaign against the Islamic State of Iraq and the Levant (ISIL) group.

The request came up in meetings that Antony Blinken, deputy national security adviser, and other US officials had with senior Iraqi officials last week on a trip to Baghdad and other parts of Iraq, a senior Obama administration official said on Tuesday.

The senior official, who briefed a small group of reporters on condition of anonymity, did not say how many more advisers were requested.

The US has about 1,400 military advisers and diplomatic security personnel in Iraq.

Iraq is not requesting American ground forces and, in any event, President Barack Obama would not send them there, and any military advisers sent there would be limited to providing advice and assistance to the Iraqis doing the fighting, the official said.

A US-led coalition has launched dozens of air strikes in Iraq and Syria to try to push back advances by ISIL, whose fighters operate from a safe haven in Syria and have control over large sections of Iraq.

Lengthy campaign ahead

The US official said the campaign against ISIL is likely to take months, well into next year, and that it will take that much time to take back key areas such as the city of Mosul or Iraq's Anbar province.

As for ISIL advances against Baghdad, the official said the group had been pushed back and predicted it would not be able to take the city.

For its part, the UN has accused ISIL of "attempted genocide" against Iraq's Yazidi minority and said atrocities committed by the armed group may amount to war crimes and crimes against humanity.

"The evidence strongly indicates attempt to commit genocide," Ivan Simonovic, UN assistant secretary-general, said on Tuesday after meeting officials and displaced people in Erbil, Baghdad and Dohuk during a week-long visit.

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Tens of thousands of Yazidis have fled, fearing for their lives after being targeted for their religious beliefs.

Meanwhile, in neighbouring Syria, Kurdish defenders of the strategic border town of Kobane await reinforcements after weathering another ISIL assault.

Fighting appeared to have diminished on Wednesday after a fierce attack begun by ISIL fighters almost 48 hours earlier, including suicide bombers, witnesses and monitors said.

ISIL fighters in eastern Kobane were exchanging fire with Kurdish Peshmerga in the west and there were reports of an explosion, probably a car bomb, the Syrian Observatory for Human Rights  said.

A total of 30 ISIL fighters and 11 Kurdish fighters were killed in 24 hours, the Britain-based monitoring group said late on Tuesday, adding that ISIL was bringing in reinforcements "as a result of the daily losses in Kobane".

Air-drop controversy

Kobane has become a crucial battleground in the war against ISIL, which is fighting to extend areas under its control in Iraq and Syria where it has declared an Islamic "caliphate".

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As the Kurds continue to fight ISIL, the Pentagon said that the vast majority of military supplies air-dropped near Kobane had reached the Kurdish fighters they were intended to help, despite an online video showing ISIL fighters with a bundle.

Rear Admiral John Kirby, the Pentagon press secretary, said experts were analysing the video and trying to determine if the bundle was the one the department reported earlier had fallen into the hands of ISIL or if it was a second bundle in the group's possession.

Pentagon officials said a US airdrop had delivered 28 bundles of military supplies to Syrian Kurdish fighters near Kobane on Sunday, and reported that one had fallen into the hands ISIL.

The Pentagon later said it had targeted the missing bundle in an air strike and destroyed it.

An Iraqi Kurdish official said 21 tonnes of supplies had been air-dropped to the Kurds in Kobane.

Source: Al Jazeera and agencies