President Trump on Monday dismissed the testimony of two former Obama administration officials, saying "the Russia-Trump collusion story is a total hoax."

Trump tweeted Monday evening that acting Attorney General Sally Yates' testimony before a Senate Judiciary subcommittee was "old news" and referenced Director of National Intelligence James Clapper's statement that there is "no evidence" of collusion between Trump's presidential campaign and Russia.

"Sally Yates made the fake media extremely unhappy today --- she said nothing but old news!" Trump wrote on Twitter.

"Director Clapper reiterated what everybody, including the fake media already knows- there is "no evidence" of collusion w/ Russia and Trump," he added.

Yates and Clapper both testified in front of a Senate Judiciary subcommittee Monday afternoon about Russia's attempts to interfere in the United States' presidential election.

Yates said during the hearing that she warned the White House that former National Security Advisor Michael Flynn may have been vulnerable to being blackmailed by the Russians.

Clapper testified that while the Intelligence Community did not assess the impact Russia's actions had on the election, its declassified report did conclude there was "no evidence of influencing voter tallies."

Clapper also testified that he is not aware of any evidence of collusion between Trump campaign staff and Russia.

The president also tweeted that there was no collusion between his campaign staff at the Kremlin.

"The Russia-Trump collusion story is a total hoax, when will this taxpayer funded charade end?" Trump said.

"Biggest story today between Clapper & Yates is on surveillance. Why doesn't the media report on this? #FakeNews!"