US President Barack Obama has said the Syrian President Bashar al-Assad would be held accountable if chemical weapons had been used in his country.
Obama, on a three-day visit to Israel, said the US was still investigating whether the weapons had been used.
ITV News Middle East Correspondent John May reports:
Speaking at a joint news conference in Jerusalem with Israeli Prime Minister Benjamin Netanyahu, he said:
We have been clear that the use of chemical weapons against the Syrian people would be a serious and tragic mistake.
– Barack Obama
The Assad regime must understand that they will be held accountable for the use of chemical weapons or their transfer to terrorists.
Earlier, Obama, who arrived in Tel Aviv today to start a three-day tour, said the US has an "unwavering commitment" to Israel's security.
Obama's day got off to a sticky start as his car, famed for its apparent robustness, broke down after a driver reportedly filled the famous vehicle with diesel instead of petrol.