Obama's comments to NBC came as the U.S. grapples with a measles outbreak traced back to California's Disneyland theme park and a day after the release of a video that purportedly showed the beheading of a Japanese journalist held by the militants.
Obama says he has watched videos of hostages being beheaded. "Every morning I get a presidential daily briefing and it gives me a pretty clear sense of the terrible stuff that's happening. And it's part of the reason why we have to be so vigilant and so aggressive in going after a vicious organization like ISIL," Obama said, using an acronym for Islamic State.
Three Americans — aid worker Peter Kassig and journalists James Foley and Steven Sotloff — were beheaded last year by the Islamic State. A fourth American being held is a woman captured last year in Syria while working for aid groups. U.S. officials have asked that she not be identified out of fears for her safety.
"Obviously this is something that is heartbreaking for the family and we want to make sure we do anything we can to make sure that any American citizen is rescued from this situation," Obama said.
On the measles outbreak that has spread to more than 100 people, Obama said children who are not vaccinated are putting infants and other people who can't get vaccinations at risk. "You should get your kids vaccinated," Obama said directly.
Some parents continue to believe debunked research linking vaccines to autism and refuse to vaccinate their children.
"I understand that there are families that, in some cases, are concerned about the effect of vaccinations," Obama said. "The science is, you know, pretty indisputable."
Obama spoke to NBC's