WASHINGTON—The U.S. is weighing a military mission in Iraq to rescue thousands of Yazidi refugees, a move that risks putting American forces in direct confrontation with Sunni fighters for the Islamic State. The proposal is still under development and hasn't been approved by President Barack Obama. U.S. officials said the rescue mission is one of many options the U.S. military is weighing after dropping food and water to dying refugees over the past six days.
"People are looking at ways to do something more than just drop water and supplies,"
one senior U.S. official said. "You can only do that for so long." Since last week, the U.S. has sought to halt the militants' advance on the Kurdish city of Erbil and to relieve Yazidis trapped by the fighters on a barren mountain range through a campaign of airstrikes and aid drops.
A rescue mission could expose U.S. forces to direct fire from the militant group Islamic State, also known as ISIS, and that is a risk Mr. Obama may not be willing to accept.
On Tuesday, the Pentagon continued to lay the groundwork for a rescue by sending another 130 military advisers to northern Iraq
to develop options the Pentagon can present to the president. The team will be made up of U.S. Marines and members of American special operations forces who have expertise in difficult missions.
The U.K. government also announced it was sending several Chinook transport helicopters to the region—a move that would position British forces to help rescue Yazidi refugees
struggling to survive in the mountain range.
Mr. Obama has repeatedly emphasized that the air campaign would be limited in scope, if not duration. At the same time, the U.S. has opened the door to offering more support to the Iraqi government if it successfully establishes a new government
. It is already covertly supplying Kurdish forces with arms, U.S. officials said.
"This is not a combat, boots-on-the-ground operation
," said Defense Secretary Chuck Hagel during a talk Tuesday afternoon with U.S. Marines at Camp Pendleton, Calif. "But, short of that, there are some things that we can continue to do—and we are doing."
No rescue operation is likely to take place until the U.S. military gets a better understanding of the scope of the crisis
. American officials don't know how many refugees are trapped in the mountains. Estimates range from several thousand to as many as 35,000 people.