WASHINGTON — U.S. President Barack Obama said Thursday that he's authorized "targeted airstrikes" in Iraq to protect American personnel and help Iraqi forces.
"We do whatever is necessary to protect our people," Obama said. "We support our allies when they're in danger."
A key concern for U.S. officials: dozens of American consular staff and military advisers working with the Iraqi military in Irbil, the largest city in Iraq's Kurdish region.
Obama said Thursday he'd directed the military to take targeted strikes against Islamist militants "should they move towards the city."
Rapid developments on the ground, where a humanitarian crisis is emerging with minority groups facing possible slaughter by Sunni Muslim extremists from the Islamic State, formerly known as ISIS, have set the stage for an increasingly dire situation.
Thousands of families from the Yazidi minority are trapped in the mountains, a senior administration officials said.
They have been without food, water or medical care after fleeing the rampaging Islamist fighters. Dozens of children have died of thirst in the intense summer heat.
Obama: 'potential act of genocide'
In addition, throngs of other refugees, many of them Iraqi Christians, are on the run -- their largest city, Qaraqosh, now occupied by fighters who gave them an ultimatum, "Convert to Islam or die."
The United States has airdropped meals and water, sending humanitarian aid to trapped minority groups on Mount Sinjar, which Islamic State is holding under siege, a senior administration official said.
Two military cargo planes flying at low altitudes dropped 5,300 gallons of water and at least 8,000 meals, a senior administration official said. No U.S. forces were on the ground, and the drop was coordinated with Iraqi troops.
"The aircraft that dropped the humanitarian supplies have now safely exited the immediate airspace over the drop area," a senior U.S. defense official said.
Obama also said he'd authorized targeted airstrikes "if necessary" to help Iraqi forces protect civilians trapped on the mountain.
"When we face a situation like we do on that mountain with innocent people facing the prospect of violence on a horrific scale, when we have a mandate to help, in this case a request from the Iraqi government, and when we have the unique capabilities to help avert a massacre, then I believe the United States of America cannot turn a blind eye," Obama said. "We can act, carefully and responsibly to prevent a potential act of genocide."
Fear of U.S. ground troops
The potential escalation of U.S. military involvement comes two years after Obama ended the Iraq war and brought home American forces.
White House spokesman Josh Earnest told reporters Thursday that there is no chance of ground troops heading back.
Obama acknowledged that many Americans are concerned about military action in Iraq.
"As Commander in Chief, I will not allow the United States to be dragged into fighting another war in Iraq, so as we support Iraqis as they take the fight to these terrorists, American combat troops will not be returning to fight in Iraq because there is no American military solution to the larger crisis in Iraq," Obama said.
Two vocal Republican Senators said in a statement that the President's actions have not gone far enough. "It should include U.S. air strikes against ISIS leaders, forces, and positions both in Iraq and Syria," read a statement by Sen. John McCain of Arizona and Lindsey Graham of South Carolina.
Iraqi forces fight back
The Iraqi air force bombed a number of targets Thursday night, Qubad Talabani, deputy prime minister of the Kurdish Regional Government, told CNN. The strikes killed at least two ISIS emirs, he said.
The United States has been sharing intelligence through reconnaissance but are not involved in any airstrikes, a senior Iraqi military official told CNN on Thursday.
The United States "almost consistently" has manned or unmanned observation aircraft over Irbil, a senior administration official said.
The ISIS fighters, armed with armored vehicles and other military hardware taken from Iraqi forces in a lightning sweep through the north earlier this year, have overrun Iraq's largest Christian town and nearby villages.
When radical Islamist fighters stormed the northern Iraqi town of Sinjar over the weekend, the Yazidi minority who call it home fled into the surrounding mountains in fear of their lives.
Other groups targeted by ISIS, which seeks to establish a Sunni caliphate stretching from Syria to Baghdad, include Shiite Muslim, Turkmen and Shabak -- all religious minorities in that region.
Fleeing people, some in cars and trucks and others on foot, got out with whatever possessions. The United Nations estimates 200,000 people heading toward Kurdistan in two recent days.
Kerry: 'ruthless thuggery'
In a statement released Thursday night, U.S. Secretary of State John Kerry called the situation a "wake-up call."
ISIS, he said, is "offering nothing to anyone except chaos, nihilism, and ruthless thuggery."
"With a gut-wrenching humanitarian crisis unfolding, and the rolls of the starving and sick growing daily, there's not a minute to waste," Kerry said. "The United States is acting and leading, and the world cannot sit by and watch innocents die."
After an emergency meeting on the situation Thursday, the United Nations Security Council issued a statement condemning the Islamists' attacks.
"The members of the Security Council reiterate that widespread or systematic attacks directed against any civilian populations because of their ethnic background, political grounds, religion or belief may constitute a crime against humanity, for which those responsible must be held accountable," the statement said
The council called on the international community to support Iraq "and to do all it can to help alleviate the suffering of the population affected by the current conflict."
Outside Irbil, the internal refugees were sleeping in parking lots or shells of buildings under construction with little access to water or any other services, CNN's Ivan Watson reported.
Kurdish officials call for U.S. or NATO airstrikes to help them fight the ISIS forces.
They also issued statements intended to boost morale of the Kurdish people, saying the Kurdish Peshmerga fighters would be able to hold off any serious threat to Irbil and other cities.
A senior State Department official said the United States also was weighing opening a humanitarian corridor to provide support to Kurdish and Iraqi forces.
Earnest, however, said while the United States would support Iraqi and Kurdish efforts, "we can't solve these problems for them. These problems can only be solved with Iraqi political solutions."
The United States has 245 military personnel in Iraq, 90 of whom are advisers. The carrier USS George H.W. Bush and other Navy ships also are in the region.
Yazidis, among Iraq's smallest minorities, are of Kurdish descent, and their religion is considered a pre-Islamic sect that draws from Christianity, Judaism and Zoroastrianism.
Most of the 500,000 or so members live in and around Sinjar in northwestern Nineveh province, bordering Iraq's Kurdish region.
The U.N. children's agency, UNICEF, said Tuesday that official reports indicated 40 children from the Yazidi minority had died "as a direct consequence of violence, displacement and dehydration" since the weekend.
"Families who fled the area are in immediate need of urgent assistance, including up to 25,000 children who are now stranded in mountains surrounding Sinjar and are in dire need of humanitarian aid including drinking water and sanitation services," it said.
CNN's Jim Sciutto and Barbara Starr reported from Washington. CNN's Catherine E. Shoichet reported from Atlanta. CNN's Tom Cohen, Ivan Watson, Dana Ford, Elise Labott, Mohammed Tawfeeq, Jim Acosta, Jamie Crawford, Steve Almasy and Hamdi Alkhshali contributed to this report.