To protect and serve.

(Fox News) — An outspoken Arizona sheriff has responded to a letter from the mayors of three border cities who asked him to tone down his comments on border security problems, saying, “feel free to ‘drink the Kool-Aid'” of Homeland Security Secretary Janet Napolitano, U.S. Attorney Dennis Burke and President Obama.

In a letter dated Feb. 14, Pinal County Sheriff Paul Babeu said his jurisdiction is the “number one pass through county” nationwide for smuggling people and drugs.

“The threat from an unsecured border is real, where 241,000 illegals were apprehended last year by the border patrol and an additional 400,000 got away just in Arizona alone!” the letter reads. “These are failing grades by anyone’s score card.”

Babeu’s letter is in response to a Feb. 9 letter he received from the mayors of Nogales, San Luis and Douglas that asked him not to “cultivate a culture of fear” regarding border security. . . .

In an interview with FoxNews.com, Babeu said he has recently increased enforcement near the border with “constant patrols” by SWAT team officers armed with AR-15s and night vision goggles. “I’m sending out deputies to meet these armed cartel members,” Babeu said Wednesday. “And we will not use less than lethal force.”

“They want us to sit and shut up,” he said. “Well, that’s not going to happen. This isn’t a time to sit on our hands and ignore the issue. It’s a time for action.”