Steve Bannon, a one-time adviser to former U.S. President Donald Trump, filed formal notice in federal court on Friday that he would appeal his conviction and sentence on two counts of contempt of Congress.

Bannon's sentence of four months in prison will be suspended as he challenges his prosecution.

In July, Bannon was found guilty of two counts of contempt of Congress for failing to turn over documents or show up to testify to a House of Representatives committee investigating the January 6, 2021 riots at the U.S. Capitol.

He was sentenced to four months in prison by a federal judge in October along with a fine of $6,500. The judge said that he wouldn't have to serve his sentence while pursuing an appeal of his conviction.

Bannon served as the White House's chief strategist during Trump's presidency in 2017. The 68-year-old far-right provocateur had triggered controversy as he helped the former president to advocate the "America First" populism and anti-immigration sentiment.

(With input from Reuters)