Story highlights Donald Trump is hitting the first three primary states with a new round of radio ads

The four 60-second radio ads are the second phase of a $300,000 ad buy

Washington (CNN) Donald Trump is hitting the first caucus and primary states with a new round of radio ads, including one national security-focused spot that mentions the terrorist attacks in Paris.

"The tragic attacks in Paris prove once again that America needs to get tough on radical Islamic terrorism," Trump says in one ad released Wednesday. "President Obama and other politicians have consistently failed us."

Trump vows once again to "bomb the hell out of ISIS" and that "no one -- and I mean no one -- will mess with us" if he is elected president.

The four 60-second radio ads are the second phase of an on-air effort Trump's campaign launched two weeks ago in Iowa, New Hampshire and South Carolina. Trump narrates two of the four ads in the $300,000 buy, while his campaign Co-Chair Sam Clovis, an influential Iowa Republican, and a female New Hampshire resident voice the remainder.

Trump's campaign has yet to release any television ads, with Trump campaign manager Corey Lewandowski calling radio "an effective means of communication." He added money was "not a factor" in deciding to do radio versus television ads, which are costlier.

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