Vice President Biden said that those who used chemical weapons in Syria "should and must be held accountable" during a speech Tuesday to the America Legion in Houston.
The vice president also said that President Obama had instructed him and other top administration officials to get in touch with foreign counterparts as the administration sketches out its response to last week's chemical attack in a suburb of Damascus.
"The president believes, and I believe, that those who use chemical weapons against defenseless men, women and children should and must be held accountable," Biden said.
Earlier Tuesday, White House press secretary Jay Carney said "there must be a response" to the attack, which rebel groups estimate left more than 1,000 Syrians dead.
"We cannot allow this kind of violation of an international norm, with all the attendant grave consequences that it represents, to go unanswered," Carney said. "What form that response will take is what the president is assessing now with his team."
Earlier Tuesday, NBC News reported that the U.S. was preparing three days of bombing attacks on Syrian targets, to begin as early as Wednesday.
Administration officials told the network the strikes would be limited in scope and aimed at sending a message to Assad in hopes of deterring a future chemical weapons attack.
Secretary of Defense Chuck Hagel told the BBC that the military was "ready to go" if orders came from Obama to begin the strikes.
“We have moved assets in place to be able to fulfill and comply with whatever option the president wishes to take,” said Hagel.
Tuesday morning, Biden met with Secretary of State John Kerry at the Naval Observatory and Obama at the White House before departing for Houston.