Australian fighter jets are being deployed to the Middle East to join the U.S.-led campaign of air strikes on jihadist targets in northern Iraq, Defense Minister David Johnston said Monday.

"We will provide a number of military platforms, up to eight Super Hornet aircraft to participate in a U.S.-led coalition in delivering air strikes," he told reporters in Baghdad after meeting Iraqi Prime Minister Haider al-Abadi.

The Lebanese army on Monday distanced itself from a video showing troops abusing Syrian detainees in an area where soldiers have battled jihadists, saying the incident was "isolated."

The video, which appeared online over the weekend and quickly provoked widespread outrage on social media, shows around 30 Syrian men lying on the ground, some with their hands bound.

Iraqi Prime Minister Haidar al-Abadi opposes the deployment of foreign ground forces in Iraq as part of efforts to combat jihadists, his office said on Monday.

During a meeting with Australian Defense Minister David Johnston in Baghdad, Abadi reaffirmed his "rejection of any ground intervention in Iraq", a statement said.

The Islamic State group called on Muslims to kill citizens of all countries taking part in the U.S.-led anti-jihadist coalition by any available means, in a statement posted online Monday.

"If you can kill a disbelieving American or European -- especially the spiteful and filthy French -- or an Australian, or a Canadian or any other disbeliever... including the citizens of the countries that entered into a coalition against the Islamic State, then rely upon Allah, and kill him," said Abu Mohammed al-Adnani, the group's spokesman.

Kurdish militia fought to defend a key border town in northern Syria on Monday after 130,000 terrified residents fled to Turkey to escape an advance by Islamic State fighters.

Amid calls for a U.S.-led coalition to support the Kurdish fighters with air strikes, the IS group issued a statement urging Muslims to kill Westerners whose countries have joined the campaign.

U.S. Secretary of State John Kerry on Sunday raised the threat of Islamic militants in Iraq and Syria directly with his Iranian counterpart in high-level talks in New York, a U.S. official said.

Kerry met Iranian Foreign Minister Mohammad Javad Zarif for more than an hour at a hotel, during which they discussed progress in nuclear negotiations and "also discussed the threat posed by ISIL," a senior State Department official said, referring to the Islamic State group.

The rise of the brutal Islamic State group can partly be blamed on President Barack Obama's failure to arm moderate Syrian rebels far earlier, said former U.S. defense secretary Leon Panetta.

It comes after the United States Congress on Thursday passed Obama's plan to train and arm moderate Syrian rebels to battle Islamic State jihadists, a key plank of his strategy to smash the militants who have overrun vast areas of Iraq and Syria.

U.S. Secretary of State John Kerry reaffirmed U.S. concern Sunday over the use of chlorine gas against civilians in Syria and warned President Bashar Assad's regime that it would be held to account.

Kerry pointed to a report by the Organization for the Prevention of Chemical Weapons that concluded with "a high degree of confidence" that chlorine has been used systematically and repeatedly as a weapon in northern Syria.

U.S. Ambassador Samatha Power predicted Sunday that the United States would not be alone if it launches air strikes against Islamic State jihadists in Syria, although she said no decisions have been reached yet.

The U.S. envoy to the United Nations' comments came as the United States puts together an international coalition to fight the IS group, which has seized large areas of Syria and Iraq in a bloody drive that has included beheadings of western hostages.

As many as 70,000 Syrian Kurds have poured into Turkey since Friday fleeing an offensive by Islamic State jihadists in northeastern Syria, the U.N.'s refugee agency said Sunday.

The UNHCR "is stepping up its response to help Turkey come to the aid of an estimated 70,000 Syrians crossing into Turkey", most in the past 24 hours, the agency said in a statement.