Sen. Richard Burr told CNBC on Wednesday the federal government and Big Tech need come together to thwart the kind of election meddling that plagued social media platforms during the 2016 presidential campaign.

Yet he also noted the need to protect people's First Amendment rights.

"We've had a partnership over the last few months that's shown great progress. And today is a continuation," said Burr, chairman of the Senate Select Committee on Intelligence.

Burr's committee was holding a Wednesday morning hearing on election security with Facebook COO Sheryl Sandberg and Twitter CEO Jack Dorsey testifying. Alphabet's Google refused to send someone from the C-suite.

Sen. Mark Warner, D-Va., vice chairman of the committee, said, "The fact that [Google] chose not to participate is pretty disappointing. They're not going to be able to escape the kind of very serious questions we have."

On the issue of regulation, Burr acknowledged in a CNBC interview that "the First Amendment is a tough thing to legislate round."