Kerry says what has happened in Syria "should shock the conscience of the world."

　　"The indiscriminate slaughter of civilians, the killing of women and children and innocent bystanders by chemical weapons is a moral obscenity," he said. "By any standard it is inexcusable. And despite the excuses and equivocations that some have manufactured, it is undeniable."

　　Syria's government denies any involvement in last Wednesday's apparent chemical weapons attack. Russia's foreign ministry says the attack could have been carried out by opponents of embattled President Bashar al-Assad so as to provoke international action against him.

　　Kerry dismissed that, saying Syria's government maintains custody of the country's chemical weapons, has the capacity to deliver them with rockets, and is determined to clear its opponents from areas attacked. He told reporters at the State Department that the Obama administration's understanding of what has happened "is grounded in facts, informed by conscience, and guided by common sense."

　　"Anyone who could claim that an attack of this staggering scale could be contrived or fabricated needs to check their conscience and their own moral compass," he said. "What is before us today is real. And it is compelling."

　　Earlier Monday, U.N. inspectors visited the site of the attack in a Damascus suburb, meeting with victims as well as doctors at a makeshift hospital.  They also took samples from the area and said they would return Tuesday.   U.N. Secretary-General Ban Ki-Moon said the inspectors' mission could deter future use of chemical weapons in Syria.

　　"The whole world should be concerned about any threat or use of chemical weapons, and that is why the world is watching Syria," he said.

　　Kerry says Syria's decision to allow those inspections is "too late to be credible," accusing Syria of trying to destroy evidence by bombing the area since Wednesday's attack.

　　Kerry says President Obama is in close touch with allies, discussions that raise the prospect of military action.  He says Obama "will be making an informed decision about how to respond to this indiscriminate use of chemical weapons." The United States has not ruled out any military options except for U.S. troops on the ground in Syria.

　　"Make no mistake. President Obama believes there must be accountability for those who would use the world's most heinous weapons against the world's most vulnerable people," he said. "Nothing today is more serious and nothing is receiving more serious scrutiny."

　　Secretary Kerry continues telephone diplomacy wtih allies in Britain, France and Canada, as well as discussions with Russia and several of Syria's neighbors in the Middle East.