President Barack Obama said Saturday that he would not give a timetable for the United States' intervention in Iraq, and warned that the current operation there could "take some time" as the U.S. military airdropped more supplies to thousands of members of an Iraqi minority who were trapped on a mountaintop after they fled the advance of the Islamic State armed group.

U.S. airstrikes launched in Iraq this week have focused on Islamic State fighters, who have captured hundreds of women from the Yazidi religious minority, according to an Iraqi official. Thousands of other civilians have fled in fear. The U.S. said the strikes are also meant to protect American personnel stationed in Irbil, the capital of the country's autonomous Kurdistan region, where the extremists have been closing in.

Speaking at a news conference from the White House's South Lawn on Saturday morning, Obama said that "so far these strikes have successfully destroyed arms and equipment that [Islamic State] terrorists could have used against Irbil."

"I'm not going to give a particular timetable [on strikes] because as I’ve said from the start, wherever and whenever U.S. personnel and facilities are threatened, it’s my obligation, my responsibility as commander-in-chief to make sure that they are protected," Obama said.

"I don't think we're going to solve this problem in weeks," Obama said. "This is going to be a long-term project."

Halgord Hikmet, a spokesman for the Kurdish security forces, told Al Jazeera that the security forces had "succeeded in reaching the mountains and opening a road for the refugees," adding that the recent U.S. airstrikes had allowed them to open up the route.

The president also said during the news conference that "we’re not moving our embassy anytime soon, we’re not moving our consulate any time soon, and that means that given the challenging security environment, we’re going to maintain vigilance and ensure that our people are safe." Many U.S. allies have backed the intervention.

The president said he was also focused on seeing the Iraqi government "getting formed and finalized."

"In the absence of an Iraqi government, it is very hard to get a unified effort by Iraqis against ISIL," he said, using the initials for Islamic State in Iraq and the Levant, an earlier name for the group.

Political deadlock over forming a new government since an inconclusive election in April has undermined efforts to confront Islamic State, which poses the biggest threat to Iraq's security since the fall of Saddam Hussein in 2003.

In his weekly address Saturday, Obama sought to reassure Americans wary of involvement in a country the U.S. withdrew forces from in 2011. “I will not allow the United States to be dragged into fighting another war in Iraq,” Obama said. “American combat troops will not be returning to fight in Iraq, because there’s no American military solution to the larger crisis there.”

But he added that when innocent people face a possible massacre and the U.S. has the ability to stop it, the nation should not look away.

Obama had earlier sent a small contingent of U.S. troops – mainly to protect the U.S. embassy and its personnel – in response to Islamic State gains. The troops have also helped provide security in cooperation with Iraq’s military.

The first drop of crates of food and water to the thousands of Yazidis trapped on a mountaintop was carried out Friday.

Yazidis belong to an ancient religion that Islamic State considers heretical. The group also sees Shia Muslims as apostates, and has demanded that Christians either convert to Islam or pay a special tax.

Underscoring the sense of alarm over human rights abuses by the group, a spokesman for Iraq's human rights ministry said the militants had seized hundreds of Yazidi women. Kamal Amin, citing reports from the victims' families, said some of the women were being held in schools in Iraq's second-largest city, Mosul.

"We think that the terrorists by now consider them slaves and they have vicious plans for them," Amin told The Associated Press. "We think that these women are going to be used in demeaning ways by those terrorists to satisfy their animalistic urges in a way that contradicts all the human and Islamic values."

American planes conducted the second airdrop of food and water early Saturday for the Yazidis trapped in the Sinjar mountains, said Pentagon chief spokesman Rear Adm. John Kirby.

Escorted by two Navy fighter jets, three planes dropped 72 bundles of supplies for the refugees, including more than 28,000 meals and more than 1,500 gallons of water, said Kirby, who spoke from New Delhi during a trip with U.S. Defense Secretary Chuck Hagel.

The extremists' “campaign of terror against the innocent, including the Yazidi and Christian minorities, and its grotesque and targeted acts of violence bear all the warning signs and hallmarks of genocide,” U.S. Secretary of State John Kerry said in a Thursday statement. “For anyone who needed a wake-up call, this is it.”

At the White House, Deputy National Security Adviser Ben Rhodes met with members of the Iraqi Yazidi community and “noted that the United States will act, carefully and responsibly, to prevent a potential act of genocide,” said National Security Council spokeswoman Bernadette Meehan.

The International Rescue Committee said it was providing emergency medical care for up to 4,000 dehydrated Yazidis, mostly women and children, who survived without food or water for up to six days hiding in the Sinjar mountains before fleeing to a refugee camp in Syria, where a civil war is raging.

For the U.S. military, which withdrew its forces from Iraq in late 2011 after more than eight years of war, the re-engagement began on Friday, when two jets dropped 500-pound bombs on a piece of artillery and the truck towing it. The Pentagon said the militants had been using the artillery to shell Kurdish forces defending Irbil, the site of a U.S. consulate and about three dozen American military trainers.

Later Friday, the U.S. launched a second round of airstrikes near Irbil, U.S. officials said. The officials, speaking on condition of anonymity because they weren't authorized to discuss the strikes publicly, said unmanned aircraft hit a mortar and four Navy F/A-18 fighter jets destroyed a seven-vehicle convoy.

Hinting at the possibility of future strikes, Defense Secretary Chuck Hagel, traveling in India, said Friday that if Islamic State fighters threaten U.S. interests in Iraq or the thousands of refugees in the mountains, the U.S. military has enough intelligence information to clearly single out the attackers and launch effective airstrikes.

Expanding from their stronghold of Mosul, Islamic State fighters have captured a string of towns and Iraq's largest hydroelectric dam and reservoir in recent weeks. Ethnic and religious minorities, fearing persecution and slaughter, have fled as their towns fell.

According to the United Nations, more than 500,000 people have been displaced by the violence in Iraq since June, bringing the total this year to well over 1 million.

In contrast to Washington's decision to invade Iraq more than a decade ago, both the airdrop and the authorization of military action against the Islamic State group were widely welcomed by Iraqi and Kurdish officials fearful of the movement's advance.

Al Jazeera and wire services. Philip J. Victor contributed to this report.