Washington: US President Barack Obama said the recent shooting rampage in Californian city of San Bernardino was an "act of terrorism".
"This was an act of terrorism, designed to kill innocent people," Xinhua quoted Obama as saying on Sunday.
It was clear that the two shooters had gone down the dark path of radicalisation, embracing a perverted interpretation of Islam that calls for war against the US and the West, Obama said.
He called on Americans not to turn against each other, saying the Muslim Americans were "friends, coworkers" of the US.
Obama also said the country should carry out stricter screening for those who come to the US without visa.
Two gunmen, US citizen Syed Farook, 28, and his wife Tashfeen Malik, 27, shot down 14 people and injured 21 others on Wednesday at a social services centre.
Reaffirming his commitment to destroy the Islamic State, US President Barack Obama said America will destroy any militant organisation that tried to harm its people but ruled out sending large scale troops on the ground as done in the case of Afghanistan and Iraq.
In a rare address to the nation from his Oval Office of the White House, Obama said his strategy to destroy ISIS is designed and supported by US military commanders and counter-terrorism experts, together with 65 countries that have joined an American-led coalition.
Obama said the threat from terrorism is real, but US will overcome it. "We will destroy ISIL (another name for ISIS) and any other organisation that tries to harm us," he said.
"Our success won't depend on tough talk, or abandoning our values or giving into fear. That's what groups like ISIL are hoping for. Instead, we will prevail by being strong and smart, resilient and relentless. And by drawing upon every aspect of American power," he added.
In his speech, Obama ruled out sending large scale troops on the ground. "We should not be drawn once more into a long and costly ground war in Iraq or Syria. That's what groups like ISIL want. They know they can't defeat us on the battlefield. ISIL fighters were part of the insurgency that we faced in Iraq," he said.
"But they also know that if we occupy foreign lands, they can maintain insurgencies for years, killing thousands of our troops and draining our resources, and using our presence to draw new recruits," said the US President.
"The strategy that we are using now -- air strikes, special forces, and working with local forces who are fighting to regain control of their own country -- that is how we'll achieve a more sustainable victory, and it won't require us sending a new generation of Americans overseas to fight and die for another decade on foreign soil," Obama said.