Iran's Supreme Leader Ayatollah Ali Khamenei yesterday accused the United States of trying to divide Iraq along sectarian and ethnic lines and urged Iraqis to withstand any such plans.

Shia Muslim power Iran wields great influence in Iraq, which has a majority Shia population. Its military advisers are helping direct Baghdad's campaign against Sunni Islamist militant group Islamic State, which seized around a third of Iraq's territory last year.

It was not clear if Khamenei was referring to a specific incident, but Iran has protested about US policy in Iraq several times this year.

"The Americans must not be allowed to consider Iraq as their personal property ... and dare to openly talk about disintegration of Iraq," Khamenei said according to his website.

"The Iraqi people, Shias, Sunnis, Kurds and Arabs have been living together peacefully but some regional countries and some foreigners are trying to amplify differences among them," he added.

In August, outgoing US Army chief of staff General Ray Odierno drew condemnation from Baghdad and Tehran when he said reconciliation between Shias and Sunnis in Iraq was becoming harder and that partitioning the country "might be the only solution."

In the instability resulting from the rise of Islamic State, Iraq's Kurds have expanded the reach of their autonomous regional government to include Kirkuk, which sits on substantial oil deposits.

During a meeting with Russian President Vladimir Putin on Monday, Khamenei called for closer bilateral ties between Tehran and Moscow to thwart what he called "Washington's plots".

Meanwhile, Australia Prime Minister Malcolm Turnbull yesterday said the IS group is weak and he has no plans to send combat troops to fight it.

His remarks contrasted with former prime minister Tony Abbott's description of IS as a "death cult".

In eastern Syria, US warplanes have destroyed 283 fuel tankers that were being used to transport oil to help fund the Islamic State group, officials said Monday. It came less than a week after another, similar strike destroyed 116 IS fuel trucks.

In Egypt, Islamic State group suicide bombers killed four people, including a judge, in an assault yesterday on a North Sinai hotel hosting judges overseeing Egypt's parliamentary polls, the government and jihadists said.

The interior ministry said a judge, two policemen and a civilian were killed in the blasts at the Swiss Inn hotel in the town of El-Arish, the provincial capital of North Sinai where Islamist militants are waging an insurgency.