Sen. Ted CruzRafael (Ted) Edward CruzOvernight Tech: Facebook faces crisis over Cambridge Analytica data | Lawmakers demand answers | What to watch for next | Day one of AT&T's merger trial | Self-driving Uber car kills pedestrian The case for a new branch of the military: United States Space Force The problem with hindsight MORE (R-Texas) on Saturday is rolling out a series of TV ads in Iowa, including one aimed at bolstering his credentials to fight terrorism if elected president. 

The ads will debut during the Big Ten Championship between Michigan State and Iowa. 

“If I’m elected to serve as Commander-in-Chief, we won’t cower in the face of evil. America will lead,” Cruz says directly into the camera. “We’ll rebuild our military. We’ll kill the terrorists. And every Islamic extremist will know, if you wage jihad against us, you’re signing your death warrant.”

The ad is particularly timely as law enforcement is investigating Wednesday's San Bernardino, Calif., shootings as an act of terrorism. 

Cruz and rival presidential candidate Sen. Marco Rubio (R-Fla.) have recently exchanged national security jabs after Cruz supported a National Security Agency reform bill this year, which is touted by privacy advocates but opposed by some Republicans who believe it will weaken U.S. intelligence activities. 

Cruz also debuted a second ad touting an endorsement from Rep. Steve King (R-Iowa). 

Ahead of the Iowa caucuses in February, Cruz ranks third in GOP presidential polls in the Hawkeye State, trailing Donald Trump and Ben Carson. 

Cruz’s camp said the ads are part of a six-figure media buy in the state. Broadcast disclosure forms show they will run until at least Dec. 18.