He used it to push his theory that the party will attempt to cheat the self-described democratic socialist out of victory: "What it could be is, you know, the Democrats are treating Bernie Sanders very unfairly and it sounds to me like a leak from Adam Schiff because they don't want Bernie Sanders to represent them.
"It sounds like it's '16 all over again for Bernie Sanders."
Mr Trump was leaving for a trip to India on Sunday when reporters asked him about the reported Russian interference.
"Nobody said it to me at all. They ought to investigate Adam Schiff for leaking that intelligence."
But Mr Schiff denied Trump's accusations in a tweet saying: "Nice deflection, Mr President. But your false claims fool no one.
"You welcomed Russian help in 2016, tried to coerce Ukraine’s help in 2019, and won’t protect our elections in 2020.
"Now you fired your intel chief for briefing Congress about it. You’ve betrayed America. Again."
The Washington Post first reported Friday that Russia sought to help Mr Sanders' campaign.
Mr Sanders said: "Unlike Donald Trump, I do not consider Vladimir Putin a good friend. He is an autocratic thug who is attempting to destroy democracy and crush dissent in Russia."
The New York Times had reported a day earlier that intelligence officials also warned lawmakers in a closed briefing that Russia was interfering to help Mr Trump.
On Sunday national security adviser Robert O'Brien disputed the idea of Russia meddling to favour Mr Trump's reelection.