WASHINGTON — Former Trump campaign aide George Papadopoulos, who pleaded guilty to lying to the FBI in the Robert Mueller probe, filed paperwork Tuesday to run for the U.S. House of Representatives in California's 25th congressional district, the seat Rep. Katie Hill recently resigned.

Papadopoulos recently expressed his interest in Hill's seat on social media.

"I'm smelling blood in the water now that Katie Hill has resigned. California's 25th congressional district is wide open for the taking," Papadopoulos tweeted Sunday.

He tweeted earlier Tuesday: "Announcement soon on my interest in Katie Hill’s soon to be vacant seat in the 25th district!"

Papadopoulos previously served a two-week prison sentence for lying to the FBI about his interactions with Russian contacts who had high-level connections to the Kremlin, including promises of “thousands of emails” and “dirt” on Hillary Clinton. He used that connection to try to set up a meeting between then-candidate Trump and Russian President Vladimir Putin.

Papadopoulos struck a plea deal with prosecutors and was the first Trump campaign aide sentenced as a result of special counsel Robert Mueller's investigation into Russian election meddling.

During the Mueller probe, Trump dismissed Papadopoulos, who served as an foreign policy adviser, as a “liar” and nothing more than the “coffee boy.”

Hill – a first-term Democratic congresswoman from California who was part of last year's historic, woman-led wave in the midterm elections – recently resigned amid an ethics probe into an alleged sexual relationship with a congressional aide, which she denied. Hill, however, did acknowledge a relationship with a campaign staffer, who is not on her congressional staff, and apologized, saying the relationship happened "despite my better judgment."

A double standard?:Katie Hill's resignation is about much more than an alleged affair and explicit photos

California's 25th District encompasses parts of northern Los Angeles County and extends into Ventura County, and was represented by Republicans for more than two decades prior to Hill's 2018 victory, in what was considered a swing district race.

A special election to fill Hill’s seat cannot be set by Gov. Gavin Newsom until she officially leaves Congress, which she has not done. It’s possible there is no special election, depending on how long she waits to leave office. That would make the next election for the seat in November 2020.

Papadopoulos could face a number of challengers, including the Republican knocked out of the House seat by Hill, Steve Knight, who has said he is considering another run.

Three other Republicans and one Democrat are also in the race. State Assemblywoman Christy Smith, the lone Democrat in the race thus far, swiftly criticized Papadopoulos amid speculation Tuesday, tweeting, "If he pled guilty to lying to the FBI – how do we know he’ll tell us the truth? We deserve someone from our community serving as our voice – not (Trump’s) wannabe political hack!”

Papadopoulos also teased running in 2020 for Congress last year. He previously confirmed to USA TODAY that he had been planning a bid for a seat in California, where he moved with his wife, Simona Mangiante Papadopoulos.

She tweeted a photo of him Monday at a lectern that reads "Make California great again!" Papadopoulos shared it, writing, "Taking back California!"