WASHINGTON — President Biden called on House Republicans to drop their impeachment inquiry after the Justice Department on Thursday criminally charged a paid FBI informant for allegedly lying about the Biden family accepting $10 million in bribes from a Ukrainian oligarch.

Biden, 81, flashed a broad smile when asked about the indictment against Alexander Smirnov, 43.

“He is lying and it should be dropped and it’s just been an outrageous effort from the beginning,” Biden told reporters in response to a question as he addressed the reported death of imprisoned Russian opposition leader Alexei Navalny.

House Republicans committed intense efforts to researching Smirnov’s allegations last year but were unable to corroborate his claims about supposed conversations he had with Mykola Zlochevsky, the owner of energy company Burisma Holdings.

Burisma Holdings paid first son Hunter Biden a salary of up to $1 million per year to serve on its board, beginning when then-Vice President Biden assumed control of US policy toward Ukraine in early 2014 in the wake of an anti-Russian uprising.

Impeachment investigators have separately uncovered evidence that Joe Biden routinely interacted with Hunter Biden and first brother James Biden’s foreign associates from a range of ventures that netted them millions of dollars during and immediately after his vice presidency.

Biden has repeatedly claimed that he “never” discussed business with Hunter or James Biden and in December claimed he “did not” interact with any of their foreign business associates.

Evidence indicates that Joe Biden as vice president interacted with Hunter and James Biden’s patrons from Russia, Mexico, Kazakhstan and Ukraine and two separate Chinese government-linked ventures.

The impeachment inquiry has also studied an alleged Justice Department coverup to shield Joe and Hunter Biden in a criminal investigation of alleged tax fraud and possible foreign lobbying offenses following claims by two IRS agents who worked on the case.