U.S. President Barack Obama called British Prime Minister David Cameron again Tuesday over possible responses to the alleged use of chemical weapons in Syria, as both leaders are weighing military actions against the Arab nation.

The White House described the phone conversation, the second since Saturday, as part of the ongoing consultations about Syria, where the government and opposition have traded blame for the chemical attacks in the suburbs of Damascus, capital of Syria, on Aug. 21, in which as many as 1,300 people were reportedly killed.

Obama and Cameron discussed "possible responses" to the attack and agreed to "stay in close consultation in the coming days," the White House said.

Washington has pinned the blame on the Syrian government and vowed to hold it accountable for this "moral obscenity."

The Washington Post reported Tuesday that Obama is considering a limited military strike on Syrian targets, involving sea-launched cruise missiles or possibly long-range bombers.

As the British armed forces are working as well on contingency plans,Cameron recalled lawmakers from their summer recess to vote on Thursday on a government motion on how to respond. Endi