Defense Secretary Jim Mattis said the U.S. has not ruled out a military response in Syria in response to a suspected chemical attack on civilians there over the weekend.
The attack targeted the last rebel-held part of the eastern Ghouta region, and dozens of people reportedly died.
"The first thing we have to look at is why are chemical weapons still being used at all when Russia was the framework guarantor of removing all chemical weapons," Mattis said.
Mattis' comments on Monday came before the United Nations Security Council discussed the attack during an emergency meeting.
President Donald Trump said he'd make a decision on how to respond to Saturday's attack "in the next 24 to 48 hours."
The Pentagon already denied the U.S. was behind a missile strike on a Syrian air base that happened early Monday morning local time. Syria and Russia have since blamed Israel for that latest attack.
Additional reporting from Newsy affiliate CNN.