The White House said that it would continue to weigh possible military action in Syria after facing fresh delays Thursday, when the British parliament voted against participation and Prime Minister David Cameron pledged not to override its decision. Obama said in an interview on Wednesday that he was "certain" Syrian President Bashar al-Assad's government was responsible for an alleged chemical weapons attack near Damascus last week, and that he and allies were weighing a military response.

"It is clear to me that the British parliament, reflecting the views of the British people, does not want to see British military action," Cameron said. "I get that, and the government will act accordingly."

Cameron had said earlier that it would be legal to take military action against Syria even if the U.N. Security Council denied authorization for such action. His government's intelligence committee said it had confirmed that a chemical attack took place in Syria last week, and that intelligence suggests it is "highly likely" that government forces were responsible.

Cameron recalled parliament in an emergency session Thursday, and told lawmakers it's likely that Assad has been "testing the boundaries" with at least 14 incidents of chemical weapons use.

Cameron said, "We must do the right thing in the right way" while ensuring that any action is proportionate, legal and designed to deter the use of such weapons.

Parliament's ultimate decision to forgo military intervention will be seen as a severe rebuff for Cameron.

Nevertheless, the United States appeared resolved to press forward.

"As we've said, President Obama's decision-making will be guided by what is in the best interests of the United States," said Caitlin Hayden, spokeswoman for the White House's National Security Council.

"He believes that there are core interests at stake for the United States and that countries who violate international norms regarding chemical weapons need to be held accountable."

Hayden noted that the U.S. would "continue to consult" with London, "one of our closest allies and friends."

Rep. Eliot Engel (D-N.Y.), top Democrat on the House Foreign Affairs Committee, told The Associated Press late Thursday that Obama was still in discussions on the timing and scope of potential action.

Engel also said administration officials told lawmakers Thursday they received intercepts of Syrian officials' communications that reportedly proved the Assad regime used chemical weapons against Syrian civilians.