Obama: 'Do not foresee scenario' of American boots on ground in Syria May 4, 2013 -- Updated 0109 GMT (0909 HKT) U.S. military intervention will not include "American boots on the ground," the president says Obama says he has discussed the issue with leaders in the region and they agree He says there is evidence of chemical weapons use in Syria "We don't know when, where or how they were used," the president says (CNN) -- U.S. President Barack Obama does not foresee a scenario of "American boots on the ground in Syria," telling reporters Friday that it would not be good for America or for that county. "By the way, when I consult with leaders in the region, who are very much interested in seeing President (Bashar al-Assad) leave office and stabilizing the situation in Syria, they agree with that assessment," Obama said during a joint news conference with President Laura Chinchilla of Costa Rica, where the president stopped during a three-day visit to the region. Even so, the president said that if the United States confirms the use of chemical weapons by the Syrian government against its people, "that's a game changer for us." He did not elaborate on what steps would be taken, repeating as he has said previously that the United States would wait until it has more details of evidence of chemical weapons use in Syria before making any decision on whether to alter strategy. We have evidence that chemical weapons have been used. We don't know when, where or how they were used," Obama said. But in recent days, the Pentagon has stepped up planning for potential military intervention in Syria, which would most likely include the use of fighter jets and cruise missiles, two administration officials, who were not authorized to discuss the matter publicly, told CNN. For now, Obama said, the United States is continuing its investigation, and working with its Middle East and European allies. The president's comments follow a number of claims in recent weeks that the Syrian government has used chemical weapons against its people in a more than 2-year-old civil war. The United Nations estimates some 70,000 people have died in the fighting. Syria has accused the United States of manipulating evidence that it used chemical weapons to pressure al-Assad to step down. In addition to Syria's possible use of chemical weapons against rebels, another concern is that parts of the government's stockpile of chemical weapons -- which analysts believe is one of the world's largest and includes sarin, mustard and VX gases -- could end up, if they haven't already, in others' hands. CNN's Barbara Starr contributed to this report.