President Obama used a rare Oval Office address on Sunday night to try to calm the nation's fears about the threat posed by Islamic extremist groups in the wake of terrorist attacks in Paris and California.

Speaking at a lectern in front of his desk, Obama detailed his administration's efforts to curb an evolving terror threat while urging the public not to give into fear or resort to Islamophobia.


Obama acknowledged that Americans' anxiousness spiked following last week's mass shooting at an office holiday party in San Bernardino, Calif., which he called an "act of terrorism designed to kill innocent people" that was inspired, but not ordered, by the Islamic State of Iraq and Syria (ISIS).

“The terrorist threat has evolved into a new phase,” Obama said. “I know that after so much war, many Americans are asking whether we are confronted by a cancer that has no immediate cure. The threat from terrorism is real, but we will overcome it.”

"We will destroy ISIL and any other organization that tries to harm us," Obama added, using the administration's preferred acronym for the radical Islamic terrorist group.

Obama did not announce any major policy changes to combat ISIS at home or abroad. But his speech was designed to inform a primetime audience of what his administration is already doing to fight the group and rally the public around his plan.

Unlike his predecessors, Obama has used the Oval Office very sparingly for high-profile speeches to the American public. Sunday's address was his first since 2010 and only the third of his presidency.

The choice of venue was meant to underscore the seriousness of the subject. But it also served as an implicit acknowledgement that the president has struggled thus far to convince the public his counterterrorism plan is working.

Obama decided to make the address on Friday and worked on his remarks throughout the weekend, according to an administration official.

Instead of making tough talk or succumbing to fear, Obama said, "we will prevail by being strong and smart, resilient and relentless and drawing on every aspect of American power."

Obama cautioned Americans against singling out Muslims, arguing that framing the fight against ISIS as a war between Islam and the West feeds into the terror network's propaganda. He called ISIS a group of "thugs" and "killers" that represents just a "tiny fraction" of the Muslim population worldwide.

But he also said Muslim communities "must confront, without excuse" ISIS online messaging that helps the group recruit foreign fighters and radicalize people in the U.S. 

"If we are to succeed in defeating terrorism, we must enlist Muslim communities as some of our strongest allies, rather than push them away through suspicion and hate," he said.

The president has come under growing pressure from Republicans and some Democrats to ramp up his response to the ISIS, and the shooting last week in San Bernardino, Calif., that killed 14 people has put the public on edge about the threat of more attacks at home.

The FBI is investigating the massacre as a homegrown terrorist attack by individuals inspired by ISIS, a type of strike officials admit is extremely difficult to prevent. One of the shooters, Tashfeen Malik, pledged her allegiance to ISIS on Facebook just before the attack, according to law enforcement.

It was the deadliest terror assault on U.S. soil by radical Islamic terrorists since Sept. 11, 2001, and it came less than a month after a string of attacks in Paris, for which ISIS claimed responsibility, left 130 dead.

Concerns about the terror network's global reach have fueled fierce criticism of the Obama administration's year-old military campaign to drive ISIS fighters from their strongholds in Iraq and Syria.

Obama has also faced criticism from Republicans, especially those running to succeed him in 2016, that he has consistently underestimated the threat the terror network poses abroad.

"The recent attacks in Paris and San Bernardino have further confirmed that radical Islamic terrorists are at war with the West," Sen. Ted CruzRafael (Ted) Edward CruzSchumer moves to break GOP blockade on Biden's State picks Bipartisan senators to hold hearing on 'toxic conservatorships' amid Britney Spears controversy GOP senators seek to block dishonorable discharges for unvaccinated troops MORE (R-Texas) said in a statement Sunday.

Cruz said the Obama administration's policies have "made the world more dangerous," adding, "It is time for a dramatic shift in both foreign and national security policy."

Obama defended his strategy of using airstrikes and a limited number of special operations forces to train local ground troops and conduct surgical raids against ISIS militants, rejecting calls for a large-scale U.S. ground presence.

He highlighted increased contributions to the 65-nation coalition fighting ISIS from allies, such as the United Kingdom and Germany, who have begun bombing attacks and pledged troops. And he touted a new effort to bomb ISIS's oil infrastructure, a key source of financing.

At home, Obama urged lawmakers to tighten visa programs that allowed Malik to come to the United States and to pass a new authorization for use of military force tailored to the ISIS fight.

And he repeated his call for Congress to make it tougher for people to carry out mass shootings by passing new gun regulations, including banning people on the government's no-fly list from purchasing firearms.

"I know there are some who reject any gun safety measures. But the fact is that our intelligence and law enforcement agencies, no matter how effective they are, cannot identify every would-be mass shooter," he said. "What we can do, and must do, is make it harder for them to kill."

Those calls have run into heavy resistance from gun-rights groups, who defeated Obama's last gun-control push after the 2012 mass shooting at an elementary school in Newtown, Conn. Groups such as the National Rifle Association say the no-fly list measure would violate people's due process rights since people on that list have not been convicted of a crime.

It's not clear if Obama's bid to retool his message on terrorism will pay dividends.

Polls show widespread public disapproval of the president's strategy to fight the group, something that could damage his party's prospects of holding onto the White House next year.

Democratic presidential front-runner Hillary ClintonHillary Diane Rodham ClintonGOP political operatives indicted over illegal campaign contribution from Russian national in 2016 Clinton lawyer's indictment reveals 'bag of tricks' Attorney charged in Durham investigation pleads not guilty MORE highlighted those concerns earlier Sunday, pressing Obama to do more in the fight against ISIS.

“We’re not winning, but it’s too soon to say that we are doing everything we need to do,” she said on ABC News's "This Week."

Updated at 9:30 p.m.