Washington (CNN) Virginia Democratic Sen. Mark Warner said Sunday that he wants more Americans to accompany President Donald Trump during his summit with Russian President Vladimir Putin on Monday.

Trump is set to meet with Putin in Helsinki, Finland, as part of his foreign trip through Europe. The two world leaders are expected to meet one-on-one before allowing other aides to join in on their conversation.

Warner, who is the ranking Democrat on the Senate Intelligence Committee, told CNN's Jake Tapper on "State of the Union" that he believes Putin could take advantage of Trump.

"We need to have other Americans in the room," Warner said. "Vladimir Putin is a trained KGB agent. He may come in with maps of Syria, maps of Ukraine, and, frankly, I think he'll take advantage of this President, who we know doesn't do much prep work before these meetings."

Warner also argued that the White House needs "other individuals from his administration in the room so we know that at least someone will press the Russians on making sure they don't interfere in future US elections."

Read More