Pope Francis has called on the international community and the United Nations in particular to do all they can to stop the "systematic violence" against ethnic and religious minorities in Iraq.
In a letter to UN chief Ban Ki-moon made public on Wednesday, the pope said he was issuing an "urgent appeal to the international community to take action to end the humanitarian tragedy now under way".
"The violent attacks that are sweeping across northern Iraq cannot but awaken the consciences of all men and women of goodwill to concrete acts of solidarity by protecting those affected or threatened by violence and assuring the necessary and urgent assistance for the many displaced people as well as their safe return to their cities and their homes."
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He urged "the international community, particularly through the norms and mechanisms of international law, to do all that it can to stop and to prevent further systematic violence against ethnic and religious minorities".
The papal plea came as time was running out for thousands of Iraqi Christians and Yazidis trapped in northern Iraq after an onslaught by Islamic State jihadists sweeping through the country.
The pope's appeal did not mention US air strikes against the Islamic State militants.
However, the Vatican's ambassador to the United Nations, Silvano Tomasi, spoke out at the weekend in support of US air strikes aimed at halting the advance of the militants, calling for "intervention now, before it is too late".
His admission that "military action might be necessary" was a rare exception to the Vatican's policy of peaceful conflict resolution in the wake of reports from Church figures on the ground that Christian persecution may be becoming a genocide.
Military support was needed "to stop the wolf getting to the flock to kill, eat, destroy", Rabban al-Qas, the Iraqi Chaldean bishop of Amadiyah, told Vatican radio.
The Obama administration is considering whether to launch a risky mission to rescue thousands of Yazidi refugees who are trapped on a mountain in Iraq, bringing the United States one step closer to direct combat with ISIS on the ground.
According to The Wall Street Journal, the proposal is still being considered. It is one of a range of options under review and has not yet been approved by President Barack Obama.
"People are looking at ways to do something more than just drop water and supplies," one senior U.S. official told the Journal. "You can only do that for so long."
On Tuesday, the United States sent an additional 130 military advisers to northern Iraq to continue to weigh options about how to achieve the rescue of the refugees and halt the advance of ISIS.
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"Any operation with respect to the mountain has its challenges," the official told the Journal. "Whether you try to do something by air, whether you try to do something by ground, both have inherent risks to them."
The United States, later joined by Britain, has been dropping food and water to the refugees by air. Australia is also expected to join the effort in the coming days, even as U.S. fighter jets have been bombing ISIS targets to halt their advance.