Washington (CNN) Kelly Sadler, the former White House aide who was let go after she mocked the late Sen. John McCain, is joining the pro-Trump super PAC America First Action to handle communications, CNN has learned. She is expected to start Monday.

"I'm really excited to do everything in my power to help reelect the President of the United States, by joining the great team at America First," Sadler said in a statement to CNN. "The President is solving the problems the American people elected him to do, and I can't wait to help him win another four years in office, so he can achieve even more."

Erin Montgomery, the PAC's current communications director, is stepping down.

Sadler quietly parted ways with the White House last summer after it became public that she remarked during a communications meeting that the Arizona senator's opposition to Gina Haspel being nominated as CIA director didn't matter because he was "dying anyway."

The White House never condemned Sadler's remark, but the episode did ignite a hunt for leakers inside of the West Wing, which President Donald Trump promised to personally pursue. After her comments became public, Sadler blamed Mercedes Schlapp, another communications aide, during a meeting with the President. Schlapp was in the room when Sadler levied the accusation.

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