(CNN) Deputy Attorney General Rod Rosenstein defended his handling of the Russia investigation Thursday evening, recalling how he had promised to "do it right" during his Senate confirmation hearing and "take it to the appropriate conclusion," while taking pointed swipes at what he called "mercenary critics," politicians and the news media.

"It's not our job to render conclusive factual findings. We just decide whether it is appropriate to file criminal charges," Rosenstein said, speaking at a dinner in New York where he was honored by the Armenian Bar Association.

Rosenstein went on to argue Thursday night that "some critical decisions" had been made before his tenure as the deputy attorney general. The previous administration "chose not to publicize the full story about Russian computer hackers and social media trolls" but the story later leaked to the media, he argued, and then-FBI Director James Comey then told Congress there was a counterintelligence investigation and alleged that Trump "pressured him to close the investigation."

"So that happened," Rosenstein said to laughter from the audience, before highlighting Mueller's findings of extensive Russian interference in the 2016 presidential election

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