The attack on April 7, which Syrian activists say killed more than 40 people, prompted punitive U.S., British and French airstrikes.

The chief of the international chemical weapons watchdog said on Friday that he has a team of experts ready and willing to travel to the site of this month's deadly nerve gas incident in Syria if their safety can be assured.

The Syrian government has formally approached the United Nations to ask for it to send in experts to investigate the April 4 suspected chemical attack.