George Papadopoulos was a member of Trump's foreign policy advisory panel when he ran for president in 2016. (AFP)

A former advisor to President Donald Trump who admitted lying to federal investigators about his contacts with Russians announced Monday he is running for a US Congress seat in California.

“I’m running for the 25th congressional district,” George Papadopoulos told Fox News.

“I’m here to promote the America-first agenda, and to enact legislation that has real-life consequences for the American people.”

The seat, in the suburbs of Los Angeles, was vacated this month by Democrat Katie Hill, who resigned amid lurid revelations about her private life and the publication of nude photos without her consent.

Papadopoulos, 32, was a member of Trump’s foreign policy advisory panel when he ran for president in 2016.

He was catapulted from obscurity when he pleaded guilty in October 2017 to lying to the FBI about contacts with a professor who promised to connect him to senior Russian officials.

Papadopoulos pursued a back channel that led him to contact with individuals who claimed Moscow had “dirt” on Trump’s Democratic election opponent Hillary Clinton.

He cooperated with investigators led by Robert Mueller, the special prosecutor who conducted a two-year probe into alleged collusion between the Trump campaign and Russia.

Papadopoulos spent 12 days in jail after his guilty plea, and subsequently wrote a book about what he describes as “the plot to bring down President Trump.”

Trump, currently facing likely impeachment, downplayed his connection to Papadopoulos during the case against his former aide.

But in July he tweeted out his support, wishing Papadopoulos “good luck” with his book.

In a Twitter post Papadopoulos said the nation needs “fighters, principled men/women with true conviction in the party’s platform who put America first.”

On Fox he said California, whose government and representatives are largely Democratic, has “tremendous potential,” but that “the governing apparatus and the party in this state has driven it right into the ground.”

Christy Smith, a Democrat in California’s State Assembly, is among several candidates who have announced they will run to replace Hill