GOP Sen. Jeff Flake (Ariz.) said Monday that it's unlikely that President Trump would change his rhetoric, but elected officials should call out him and his supporters on "out of bounds" tactics.

"The elected officials who continue to appear with the president at rallies where 'lock her up' chants are encouraged and routine and phrases like the president is using. I can't imagine, as an elected official, attending a rally like that and not stand up afterwards or beforehand and say, 'Don't do this, don't do this. This is not right,'" Flake told KJZZ, an Arizona NPR station on Monday.

Flake, a frequent critic of Trump's who is retiring after 2018, added that officials can't "change the president's behavior" but "we shouldn't appear with the president when he's doing this kind of thing."

"I don't think the president is going to change. I think if we're waiting for him to pivot, that time has come and gone. But as elected officials, we can stand up and say, 'Hey, this is out of bounds. This should not happen,'" Flake said.

Flake's criticism comes as Trump has blamed the media "in part" for a recent string of violence, including explosive devices that were mailed to prominent Democratic officials and CNN.

"There is great anger in our Country caused in part by inaccurate, and even fraudulent, reporting of the news," Trump said in a tweet on Monday , adding that the "Fake News Media" is the "true Enemy of the People."

Trump has drawn criticism for his tactics, which have paired calls for unity with lashing out at the media.

Flake noted on Monday that calling the media the "enemy of the people" is a phrase that "does not have a noble pedigree" and is "used by some fo the worst dictators in history.

He added that while Trump was not responsible for the pipe bombs "there's a backdrop here that we got to be much more careful and the president being the man with the biggest microphone has a unique responsibility that he has not used well."