U.S. forces shot down four Iran-backed Houthi drones Friday after the terror group fired four anti-ship ballistic missiles earlier, a senior defense official told Fox News.

The Houthis are angry about the Biden administration redesignating it as a terrorist group, which will cut off its financing. The sanctions went into effect Friday. 

The senior defense official told Fox News that the American public has gotten lulled into complacency, thinking it is easy for the Navy to keep shooting these missiles and drones down. 

IRAN DECLARES ANTARCTICA ITS PROPERTY IN DIRECT CHALLENGE TO BIDEN, GLOBAL TREATY 

Should a Houthi missile strike a U.S. warship, "the escalation that will follow is very serious and should give people pause," the official said. 

"People have gotten too used to us being really good at shooting these incoming missiles down," the official added. "They don’t realize how hard it is to do and the strain on the sailors manning the radar.

"The risk in the Red Sea right now has been normalized and routinized…very dangerous situation."  

The Houthis have initiated multiple attacks against vessels in the Red Sea. 

On Thursday, U.S. forces carried out four more self-defense strikes against the group after a U.S. Coast Guard cutter seized an Iranian weapons shipment bound for the militant group. 

"CENTCOM identified these mobile missiles, UAVs, and USV in Houthi-controlled areas of Yemen and determined they presented an imminent threat to U.S. Navy ships and merchant vessels in the region," a statement from U.S. Central Command said. "These actions will protect freedom of navigation and make international waters safer and more secure for U.S. Navy and merchant vessels."