WASHINGTON -- President Donald Trump announced he has authorized the declassification of documents related to the FBI's Russia investigation and the probe into Hillary Clinton's use of a private email account, part of his efforts to cast aspersions on his political enemies as he falls further behind in his bid for reelection.

"I have fully authorized the total Declassification of any & all documents pertaining to the single greatest political CRIME in American History, the Russia Hoax," Trump tweeted Tuesday.

"Likewise, the Hillary Clinton Email Scandal. No redactions!" Trump said.

Former FBI Director James Comey told a Senate committee last week that the inquiry into whether people close to Trump conspired with Russia to interfere in the 2016 election was largely conducted "by the book" but that specific aspects of the inquiry fell short.

Pressed by Senate Judiciary Chairman Lindsey Graham, who said the probe was based on faulty assumptions and evidence tampering, Comey said he found the shortcomings -- which included doctoring an email from the CIA -- "deeply disturbing." But he backed an inspector general's report that concluded that the probe was valid and not driven by bias in the bureau's leadership.

Senate Republicans are trying to put the spotlight back on what they said was a politically motivated probe meant to undermine Trump's candidacy in 2016 and, later, his presidency.

The debate comes after U.S. intelligence agencies have once again assessed that Russia is interfering again in the 2020 presidential race to aid Trump by denigrating his rival, former Vice President Joe Biden. Trump has said U.S. officials should be more focused on China, not Russia.