Story highlights The U.N. declares its highest level of emergency 
 
 U.S. military assessment determines far fewer Yazidis trapped than feared 
 
 100 Yazidi women and children are being held captive, ISIS commander tells CNN 
 
 ''I can confirm those women and children have entered Mosul,'' ISIS commander says 
 
 A mass evacuation of Yazidis hiding from extremist fighters on Iraq's Sinjar Mountains is unlikely following an assessment by the U.S. State Department and military that found far fewer people trapped than previously feared.  WASHINGTON — Defense Department officials said late Wednesday that United States airstrikes and Kurdish fighters had broken the Islamic militants’ siege of Mount Sinjar, allowing thousands of the Yazidis trapped there to escape. Rear Adm. John Kirby, the Pentagon press secretary, credited American airstrikes and humanitarian airdrops as well as efforts of the Kurdish pesh merga fighters in allowing “thousands of Yazidis to evacuate from the mountain each night over the last several days” and to escape the militants from the Islamic State in Iraq and Syria. The group has waged a brutal campaign while seizing large swaths of northern and western Iraq, aiming to establish a caliphate -- an Islamic state -- that stretches from Syria to Iraq. Some of the U.S. airstrikes have been aimed at keeping militants from advancing on Irbil, the capital of the largely autonomous Iraqi Kurdish region and home to a U.S. consulate. The assessment team joins 90 U.S. military advisers already in Baghdad and 160 in a pair of operations centers — one in Irbil and one in Baghdad, the central government's capital — working with Iraqi security forces.
– It looks like the US won't have to launch a mass evacuation of Iraqis trapped on a mountain after all. A small team of American military personnel who spent 24 hours on Mount Sinjar said US airstrikes seem to have done the trick—most of the trapped Yazidis who wanted to flee to safety have done so, reports the New York Times. As a result, defense chief Chuck Hagel said a rescue mission is "far less likely now," reports the AP. Exact numbers weren't available, but CNN quotes a Pentagon spokesman as saying that "far fewer" Yazidis were on the mountain than expected. He estimated "several thousand" but said many wanted to stay there because their homes are nearby. Earlier, the US deployed 130 troops to Iraq, and President Obama said he would be willing to use those troops as part of a rescue mission.