Obama: Don't let 'death cult' IS divide America

In a rare televised address, US President Barack Obama outlined his counter-terrorism policies following a shooting in San Bernardino that killed 14 people.

Obama said the Muslim couple who mounted the attack "had gone down the dark path of radicalisation, embracing a perverted interpretation of Islam that calls for war against America and the West.

"They had stockpiled assault weapons, ammunition and pipe bombs. So this was an act of terrorism," he said in the rare televised primetime address to the nation, only the third he has delivered from the White House Oval Office.

“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.”

Obama reiterated that the US will refuse to recognise the Islamic State group's legitimacy.

“ISIL (a different acronym for IS) is not ‘Islamic’. No religion condones the killing of innocents, and the vast majority of ISIL’s victims have been Muslim. And ISIL is certainly not a state. It is recognised by no government, nor the people it subjugates. ISIL is a terrorist organisation, pure and simple. And it has no vision other than the slaughter of all who stand in its way.”

He also emphasised that IS posed a threat to the US.

“ISIL poses a threat to the people of Iraq and Syria, and the broader Middle East - including American citizens, personnel and facilities. If left unchecked, these terrorists could pose a growing threat beyond that region - including to the United States.”

Obama promised to continue to conduct a “systematic campaign of airstrikes” against IS, and said the US will “hunt down” the armed group “wherever they are”.

Obama called on Sunday for tougher gun controls in the wake of the California shootings, starting with a ban on gun purchases for anyone on a US government no-fly list.

"To begin with, Congress should act to make sure no one on a no-fly list is able to buy a gun," Obama said in a rare televised address from the Oval Office.

"What could possibly be the argument for allowing a terrorist suspect to buy a semiautomatic weapon? This is a matter of national security."

The US president cautioned Americans to not succumb to fear or discriminate against Muslims.

“Muslim-Americans are our friends and our neighbours, our co-workers, our sports heroes. And, yes, they are our men and women in uniform who are willing to die in defence of our country,” he said. “We have to remember that.”

"ISIL does not speak for Islam. They are thugs and killers. Part of a 'cult of death'," he said. "They account for a tiny fraction of a more than a billion Muslims around the world."

"If we're 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."

Republicans have demanded that Obama back a full-scale deployment of NATO ground forces to Syria and resume controversial interrogations at Guantanamo Bay, which the president wants to close.

Conservatives have also criticised Obama's refusal to use the phrase "radical Islam" which the White House says would confer on terrorists the legitimacy of a faith they have betrayed.