U.S. President Barack Obama on Friday called French counterpart Francois Hollande and British Prime Minister David Cameron to discuss possible measures to take to punish Syrian President Bashar Assad's government for allegedly using chemical weapons against the opposition.

The White House said in a statement Obama and Hollande spoke " as part of their continuing consultations regarding the Assad regime's use of chemical weapons on August 21."

"The two leaders agreed that the international community cannot tolerate the use of chemicals weapons and must hold the regime accountable and send a strong message that the use of chemical weapons is not acceptable," said the statement, emphasizing the United States "will continue to consult closely with France on Syria and other global security challenges."

In their phone conversation, both Obama and Cameron said that the use of chemical weapons is "unacceptable and cannot be tolerated," according to a separate White House statement. It said Obama and Cameron also agreed to continue to consult closely on Syria and the broad range of security challenges.

Obama is poised to order strikes against Syria, after presenting "evidence" it said incriminated the Assad government. However, Britain has already bailed out of the possible military action, and France has signaled it would join the United States in carrying out such strikes.