SAN JOSE, COSTA RICA - President Obama tonight said he does not foresee any scenario that would require U.S. boots on the ground in Syria, as he vowed to "apply every pressure point" to the Assad regime.

"As a general rule, I don't rule things out as commander in chief because circumstances change and you want to make sure that I always have the full power of the United States at our disposal to meet American national security interests," Obama said at a joint press conference with Costa Rican President Laura Chinchilla.

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"Having said that, I do not foresee a scenario in which boots on the ground in Syria, American boots on the ground in Syria, would not only be good for America, but also would be good for Syria," he said.

AP Photo/Pablo Martinez Monsivais

The U.S. is continuing to investigate whether the Syrian government used chemical weapons against its own people.

"We will stay on this," Obama said. "If in fact, there is a kind of systematic use of chemical weapons inside of Syria, we expect that we're going to get additional further evidence and at that point absolutely, we will present that to the international community."

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Obama reiterated that the use of chemical weapons by the Assad regime would be a "game-changer" and said that any additional steps will be taken based on information on the ground and in the best interest of U.S. security.

"When we leap before we look then, not only do we pay a price, but we often see unintended consequences on the ground," he said. "It's important for us to do it right."