In a speech to the nation Sunday on the terrorism threat facing the United States in the wake of recent attacks in Paris and California, President Barack Obama outlined a strategy to destroy the Islamic State terrorist group. "America will prevail," he said.

"The threat from terrorism is real, but we will overcome it."

The president forcefully rejected the idea of a ground war in the Middle East, which some Republicans -- including some presidential candidates -- have advocated. "We should not be drawn once more into a long and costly ground war in Iraq or Syria," he said. "That’s what groups like ISIL want." The extremists "know that if we occupy foreign lands, they can maintain insurgencies for years, killing thousands of our troops, draining our resources, and using our presence to draw new recruits."

Obama outlined a four-step strategy to combat ISIS, including hunting down terrorists in any part of the world, providing training and equipment to Syrian and Iraqi forces on the ground, working with allies to disrupt terror plots and cut off financing, and working with the international community to a political resolution to the civil war in Syria.

“We will destroy ISIL and any other threat that tries to harm us,” the president said. “We will prevail by being strong and smart, resilient and relentless, and by drawing upon every aspect of American power.”

Obama called on Congress, which has resisted all gun control measures, to ensure that no one on a no-fly list is able to buy a gun, and to make it more difficult for people to obtain assault weapons. "What could possibly be the argument for allowing a terrorist suspect to buy a semi-automatic weapon?" he said. "This is a matter of national security." 

He also asked Congress to vote on a formal Authorization for Use of Military Force to signal bipartisan support for the airstrikes and special operations that the U.S. has been using to combat the Islamic State group in Iraq and Syria, adding that he has been ordering thousands of airstrikes against ISIS targets for more than a year.

Obama_OvalOffice_Dec62015 U.S. President Barack Obama speaks about counter-terrorism and the United States' fight against ISIS during an address to the nation from the Oval Office of the White House in Washington on Dec. 6, 2015. Photo: Reuters/Saul Loeb

“I think it’s about time for Congress to vote to demonstrate that the American people are united and committed to this fight,” he said.

Obama explicitly described last week's San Bernardino shooting as an act of terrorism -- though not "Islamic terrorism" -- but said there is no evidence the shooters were directed by an overseas group, nor part of wider conspiracy on American soil.

"This was an act of terrorism designed to kill innocent people," he said of the attacks that killed 14 people in California last week. "It is clear the two of them had gone down the dark path of radicalization."

Obama said the threat from terrorism has evolved into a new phase over the past several years, with the rise of the Internet “erasing the distance” between countries and allowing terrorists to “poison the minds” of people such as the 2013 Boston Marathon bombers and the San Bernardino shooters.

“As we’ve become better at preventing complex multifaceted attacks like 9/11, terrorists turn to less complicated acts of violence like the mass shootings that are all too common in our society,” he said. “Since the day I took this office, I have authorized U.S. forces to take out terrorists abroad precisely because I know how real the danger is.”

Obama urged Americans not to frame the fight against terrorism as a war between the West and Islam. "That kind of divisiveness, that betrayal of our values plays into the hands of groups like ISIL," he said. "Muslim Americans are our friends and our neighbors, our co-workers, our sports heroes — and, yes, they are our men and women in uniform who are willing to die in defense of our country." He denounced the ideas of registering Muslim-Americans, which has been floated by Republican presidential candidate Donald Trump, employing religious tests for refugees or creating a database tracking Muslims in the country. 

obama3 President Barack Obama, speaking from the Oval Office on Sunday, Dec. 6, 2015, addresses the country about the terrorism threat to the United States and the recent attack in San Bernardino, California. Photo: Saul Loeb-Pool/Getty Images

But he also called on Muslims in America and abroad to reject the extremist Islamic ideology that has become a global threat. "This is a real problem that Muslims must confront, without excuse," he said.

“ISIL does not speak for Islam,” he said. "They are thugs and killers, part of a cult of death. And they account for a tiny fraction of a more than a billion Muslims around the world, including millions of patriotic Muslim-Americans who reject their hateful ideology."

Obama said he has ordered the departments of State and Homeland Security to review the visa process by which the female San Bernardino shooting suspect entered the country. Tashfeen Malik was a Pakistani citizen who entered the U.S. in July 2014 on a fiancé, or K-1, visa that allows the overseas fiancé of an American citizen to come into the country under condition that the couple marry within 90 days of entering.

The recent attacks, which claimed the lives of 130 people in Paris and 14 in San Bernardino, have intensified the pressure on the president to reassure Americans that he has a viable plan to protect the U.S. from terror attacks and combat homegrown radicalization. Obama has faced widespread criticism for seeming slow to respond to the rise of the Islamic State group and downplaying the threat it poses to the country. Amid heightened fears of a Paris-style massacre and sinking public trust in his administration’s ability to defend the nation, Obama pledged to use “every single aspect of American power” to destroy ISIS.

The president rarely addresses the public from the Oval Office, preferring to stand at a podium in the White House East Room. Sunday’s venue is meant to emphasize the significance Obama places on the speech’s topic.

He ended by saying that "freedom is more powerful than fear," and that he was confident America would defeat the terrorist threat.