Secretary General Ban Ki-moon briefs the United Nations Monday on what chemical weapons inspectors found when they conducted an investigation in Syria.
The team took soil samples from the Damascus suburbs and blood samples from the civilian victims of last month's poison gas attack.
Its mission was not to assign blame but to confirm that an attack took palce. But the United States says it is beyond any reasonable doubt that Bashar al-Assad's military was responsible.
U.S. Secretary of State John Kerry says the threat of force against Syria is real if that country fails to live up to its agreement to rid itself of chemical weapons.
Kerry said in Jerusalem Sunday that the Assad government needs to understand that the United States is committed to this goal.
Israeli Prime Minister Benjamin Netanyahu, who met with Kerry, said deeds, not words, count. He said Syria proves that if rogue regimes have weapons of mass destruction, they will use them.
Netanyahu said the world's determination on Syria will directly impact Iran, which is suspected of building a nuclear weapon. Israel sees Iran as a direct threat to its existence.
The United States and Russia announced agreement Saturday on a plan to end Syria's chemical weapons program. It includes a requirement for the Assad government to submit a comprehensive list of such weapons in one week. Syria is promising to comply.
But the civil war in Syria is showing no signs of easing. Government warplanes on Sunday bombed rebel areas outside Damascus. There is no word so far on casualties.