What to Expect From President Obama's Rare Oval Office Address

President Obama will deliver a rare primetime address to the nation Sunday.

WASHINGTON, D.C.— -- With the country still reeling from the San Bernardino, California, shooting that left 14 dead and 21 injured, President Obama is expected to deliver a message of reassurance today, in a rare address to the nation from the Oval Office.

According to a senior administration official, Obama will take a "just the facts" tone, updating on the investigation, providing an overview of what the the government is doing to combat the threat of home-grown, ISIS-inspired terrorism, and what else needs to be done based on what has been learned so far from this attack.

He is expected to be more direct in branding the shooting as terrorism than he was Saturday in his weekly address.

"As President, my highest priority is the security and safety of the American people," he said Saturday. "This is work that should unite us all -- as Americans -- so that we're doing everything in our power to defend our country."

According to the senior administration official, the speech this evening will not be a political speech, and there will be no big call for action on gun control.

That would be a change from his previous statements on terrorism in the wake of the Paris and San Bernardino attacks, where has talked most passionately about guns and refugees.

In terms of any potential announcement on executive action on gun control, White House officials tell ABC News not to expect any major policy announcements in the president's speech.

It's been more than five years since Obama used the Oval Office to deliver an address to the nation, when he announced the end of U.S. combat operations inside Iraq.