Tribe, a vocal critic of the president, was responding to a report that spies reacted to this week's G-7 summit by describing Trump as either an asset or "useful idiot" for Russian President Vladimir Putin.
"Of course he’s both," Tribe tweeted. "Trump has been a Russian asset AND an idiot, how useful is unclear, from the beginning."
His comments echoed those of other commentators and politicians who alleged the president welcomed Russian interference in the 2016 election.
Former Special Counsel Robert Mueller's report was unable to conclude Trump participated in a conspiracy, but House Democrats have pointed to certain findings they said indicated some form of collusion, as well as obstruction of Mueller's investigation.
Russia was disinvited from the political forum known as the Group of Eight, or G-8 after the annexation of Crimea in 2014. Trump has panned the decision to disinvite Russia and offered support for reconsidering its place in the group.
Tribe has a long history of attacking the president, at one point blasting him as a "racist" and accusing him of trying to "reverse the outcome of the Civil War" following the president's indication he would do away with birthright citizenship.
"Over half a million lives were lost in that sacred cause. If you agree we can’t let this lunatic get away with that, SAY SO!!! If you’re silent, you’re complicit," Tribe added in an apparent warning to Trump's supporters.