Google is making a mistake by not sending CEO Sundar Pichai to testify in front of a Senate committee about election interference, Sen. Mark Warner, D-Va., told CNBC on Wednesday.

The Senate Select Committee on Intelligence is holding a hearing next week to address the issue of Russian meddling in the 2016 presidential election and how to move forward.

Twitter CEO Jack Dorsey and Facebook COO Sheryl Sandberg are both expected to attend. However, Google's CEO is not, said Warner, vice chair of the committee. Instead, the company planned to send a lower-level executive.

"We want to talk about solutions. We've asked for the most senior executives. … [Google] ought to be part of this discussion and dialogue," Warner said on "Power Lunch."

"Chances are there's going to be an empty chair there. And I think there will be a lot more questions raised that could have been actually dealt with if they sent a senior decision-maker and not simply their counsel."

Google has been under fire recently from both sides of the aisle. On Tuesday, President Donald Trump doubled down on his threats against Google, accusing the search engine of altering results to prioritize negative coverage and left-leaning outlets.

"Google has really taken advantage of a lot of people and I think that's a very serious thing and it's a very serious charge," Trump told reporters. "They better be careful because they can't do that to people."

A Google spokesperson responded on Tuesday, "When users type queries into the Google Search bar, our goal is to make sure they receive the most relevant answers in a matter of seconds."

When it comes to dealing with potential election interference, Google's parent, Alphabet, along with Twitter and Facebook, removed accounts tied to Russian and Iranian propaganda efforts.

Earlier this year, 13 Russians were indicted for alleged attempts to interfere in the U.S. presidential election. The latest Iranian activity was exposed by cybersecurity firm FireEye.

Warner said the issue isn't going away anytime soon. And while the U.S. is better prepared to defend against interference, he said potential adversaries are also getting better.

"We're just seeing the first generation," he said.

Google did not immediately respond to a request for comment on Warner's remarks.

— CNBC's Ryan Browne and Reuters contributed to this report.