ST.PETERSBURG, Russia (AP) — Russian President Vladimir Putin says a chemical attack in Syria was a provocation against Syrian President Bashar Assad.

Speaking at an economic forum in St. Petersburg on Friday, Putin strongly reaffirmed Russia's view that Assad's forces weren't responsible for a fatal chemical attack in Syria in April.

The U.S. in April struck a Syrian air base with cruise missiles after accusing Assad's military of killing scores of civilians with a nerve agent launched from the base.

Putin said the attack was a provocation intended to put the blame on the Syrian ruler, insisting that "Assad didn't use those weapons."

He said Russia had offered the U.S. and its allies the chance to inspect the Syrian base for traces of the chemical agent and criticized them for their refusal to do so.