Former New York Rep. George Santos announced a surprise comeback campaign while in attendance at the State of the Union (SOTU) address.

Santos, who attended President Biden's speech on Thursday, posted an announcement for his campaign to social media site X while the SOTU address was still ongoing.

"I just witnessed a weak, frail president deliver spin and lies to the American people from inside the chambers. I have made several personal sacrifices in the name of serving the American people. My promise is that I will never back down because of my love for this country," Santos wrote.

EX-REP GEORGE SANTOS RETURNS TO CAPITOL HILL FOR BIDEN'S STATE OF THE UNION ADDRESS

"New York hasn’t had a real conservative represent them since I left office arbitrarily, thanks to RINO, empty suits like Nick Lalota," the former congressman continued. "He is a willing to risk the future of our majority and the future of this country for his own political gain. After a lot of prayer and conversation with my friends and family, I have made a very important decision that will shake things up."

While Santos was previously elected to and then expelled from New York's 3rd Congressional District, the former lawmaker announced he was running against fellow Republican Rep. Nicholas Lalota in the 1st Congressional District.

Santos wrote, "Tonight, I want to announce that I will be returning to the arena of politics and challenging Nick for the battle over [New York 1st Congressional District]. I look forward to debating him on the issues and on his weak record as a Republican. The fight for our majority is imperative for the survival of the country."

EMBATTLED GOP REP GEORGE SANTOS EXPELLED FROM HOUSE

The former New York Republican congressman was expelled in the wake of a damning House Ethics Committee report that found he misused campaign funds on luxury items and OnlyFans, among other things.

Santos has not been convicted of a crime, but he has been indicted on multiple counts related to wire fraud, identity theft, falsification of records, credit card fraud and other charges. He has pleaded not guilty.

Santos told reporters it was his first time being back in the building since he was booted from the House of Representatives late last year along bipartisan lines, with 105 of his fellow Republicans joining Democrats in voting him out.

He said he came to watch the primetime address, noting that as a former member he still retains privileges that include entry to the House floor when the body is in session.

"I was just visiting with some of my colleagues in a very bipartisan fashion," Santos said.

Fox News Digital's Elizabeth Elkind contributed to this report.