The strikes were announced shortly after President Donald Trump told reporters in the Oval Office that "you're going to find out" if the U.S. will respond.
The strikes are in retaliation for the deaths of three Americans in Palmyra, Syria, on Saturday.
Hegseth said he won't release the full unedited version of video showing a Sept. 2 attack on a suspected drug boat that killed 11 people.
President Trump, after initially saying he had "no problem" with releasing the video of the Sept. 2 boat strike that killed two survivors, is now reversing course.
Workers at the Louvre Museum voted Monday for strikes to protest their work conditions, a ticket-price hike for non-European visitors and security weaknesses that a brazen daylight theft of France's Crown Jewels highlighted in October.
A Navy admiral told lawmakers that there was no "kill them all" order from Pete Hegseth as Congress scrutinizes an attack that killed two survivors of an initial strike on an alleged drug boat.