Kerry and his team began two days of meetings with their counterparts in Russia on Thursday.
"This is not a game," Kerry said. "It has to be real. It has to be comprehensive. It has to be verifiable. It has to be credible. It has to be timely and implemented in a timely fashion. Finally, there ought to be consequences if it doesn't take place."
Below, more from the AP:
GENEVA -- U.S. Secretary of State John Kerry is rejecting Syrian President Bashar Assad's suggestion Thursday that he begin submitting data on his chemical weapons arsenal one month after signing an international chemical weapons ban.
Speaking at a news conference with Russian Foreign Minister Sergey Lavrov, Kerry noted that Assad said a 30-day lead time would be standard.
"There is nothing standard about this process," Kerry said, because Assad has used his chemical weapons.
"The words of the Syrian regime in our judgment are simply not enough."
Kerry cautioned that a U.S. military strike could occur if Assad doesn't agree to dismantle his chemical arsenal properly.
He said, "There ought to be consequences if it doesn't take place."
Lavrov said the dismantling "will make unnecessary any strike against the Syrian Arab Republic."