All the facts from Syria
WASHINGTON (AP) -- President Barack Obama says the United States doesn't know how or when chemical weapons were used in Syria or who used them.
Obama told reporters at a news conference Tuesday he's got to make sure he has the facts before deciding how to respond to evidence that chemical weapons were used.
Obama has said there is "some evidence" that President Bashar Assad's government used chemical weapons against his people. But he said that's a preliminary assessment based on intelligence information.
Obama repeated his statement that the use of chemical weapons would be a "game changer" in the region. But he said the international community has to be completely confident in the assessment.
Boston review underway
Obama says a national security review following the Boston Marathon bombings will look at whether there is more the government can do to stop people within the United States who might become radicalized and plan terror attacks.
One of the dangers the U.S. faces now, Obama said, is people who might decide to attack because of "whatever warped, twisted ideas they may have."
Obama said that based on what he's seen so far, the FBI and the Department of Homeland Security did what they were supposed to before the attack.
But he said the review was needed to find out whether more can be done to prevent this type of attack by people within the United States who may become radicalized.
Obama said, "This is hard stuff."
Closing Guantanamo Bay
Obama says he's going to try again to close down the prison for terrorist suspects at Guantanamo Bay, Cuba.
The president says he's asked a team of officials to review the issue and will take it back to Congress again. He told the news conference he's not surprised there are problems at the facility, where 100 of the 166 inmates are on a hunger strike.
Obama ordered the detention center closed upon taking office, but Congress thwarted him and made it harder to move prisoners elsewhere. Releases and transfers have since become rare, giving detainees little hope of ever being released.
Health care law
Obama argues that his signature health care law is already benefiting most Americans even if they don't know it.
The president says despite what he calls "sky is falling" predictions, the Affordable Care Act's provisions are already in place for those with health insurance.
He says what's left is to help those Americans who don't have health care coverage to obtain it. He acknowledged that is "a big undertaking" and predicted there could still be some glitches as the details are worked out.