WASHINGTON -- The United States is planning a multinational mission to whisk displaced people to safety in Iraq and it appears there may be a supporting role for Canada.

The U.S. announced Wednesday that it was talking to several countries including Canada about helping Yazidis, Iraqi Christians, and other people who have become displaced by the advance of Islamist fighters.

At a White House briefing, deputy national security adviser Ben Rhodes said the U.S. was taking up offers to help those who are under threat from the al Qaeda splinter group, the Islamic State of Iraq and the Levant.

"We have offers of support from a number of allies like France, Australia, Canada," Rhodes said.

"We'll be in discussions with them about what they can do both as it relates to helping the Yazidi population ... but also, more broadly, helping bring relief to the displaced persons in northern Iraq, which includes not just Yazidis but an enormous number of Iraqi Christians and others who have been driven from their homes by ISIL."

It's expected that several countries would play a humanitarian-assistance role while U.S. special forces assess options for a more muscular military mission to help move tens of thousands of people away from the area.

The U.S. has stepped up its Iraqi engagement in recent days, after thousands became stranded on a mountain, facing starvation and the threat of being killed by Islamist rebels.

It has also vowed to fight off rebel incursions that threaten areas where there are Americans -- notably Baghdad and the oil-rich Kurdish region, which has a considerable U.S. business and diplomatic presence.

Last weekend, Canada promised $5 million in aid for displaced Iraqis, with nearly half the money going to international groups like the Red Cross and the rest set to be spent following consultation with allies.

The Canadian government wouldn't confirm that additional assistance might be forthcoming but one senior official said Wednesday: "I expect that we will be in a position to announce next steps soon."

Meanwhile, British Prime Minister David Cameron cut short his holiday to attend an emergency meeting on Iraq. He promised to help "get these people off that mountain." The Royal Air Force has already provided several drops of humanitarian supplies, and additional British jets and helicopters are being deployed to the region.

France announced it would start supplying "sophisticated" arms to the Kurdish forces fighting Sunni extremists.

The U.S. has launched about eight airstrikes in the region and is preparing a more elaborate mission, the details of which Rhodes said should become clear within days. He said U.S. military analysts were assessing different possible operations.

Rhodes was adamant about one thing: U.S. President Barack Obama, who removed U.S. combat troops from Iraq three years ago, would not be sending them back in. The president has repeatedly promised not to send in combat troops, and has spoken publicly about his concerns about so-called mission creep.

"In any effort, there are always dangers involved," Rhodes noted when asked whether a rescue mission could devolve into a firefight.

"Well, look, any time you have -- I mean, even now as we speak we have pilots flying over Iraq. That always carries with it danger," he said.

So far, U.S. lawmakers have been extremely supportive of the Obama administration's operations in Iraq.

That's a stark contrast with last year, when his musings about airstrikes in Syria met with a wall of resistance.

Polls suggest American public opinion has become anti-war in recent years, following deadly and costly years-long conflicts in Afghanistan and Iraq. Obama was elected on a promise to end the latter war, and has repeatedly stated his reluctance to get drawn back into Iraq.

In the latest airstrike Wednesday, U.S. military officials said a drone aircraft attacked and destroyed an armed truck operated by Islamic militants near Mount Sinjar, in northern Iraq.

The U.S. Central Command said in a brief statement that the targeted truck was located in the vicinity of a checkpoint operated by fighters of the Islamic State.