Gabrielle Giffords resigns from Congress amid tributes

Arizona Representative Gabrielle Giffords has formally resigned from the US Congress, receiving a standing ovation from her colleagues.

Ms Giffords, shot by a lone gunman during a constituency meeting in January 2011, announced on Sunday she was resigning to complete her recovery.

Before the ceremony, the House voted unanimously in favour of a final bill she introduced, on immigration.

In her resignation letter, Ms Giffords promised to return to public life.

Close friend Debbie Wasserman-Schulz, a Florida congresswoman and chair of the Democratic National Committee, fought back tears as she stood next to Ms Giffords and read out her resignation letter.

House Speaker John Boehner dabbed his eyes as he formally declared Gabrielle Giffords' resignation.

Minority Leader Nancy Pelosi, Majority Leader Eric Cantor, as well as Democratic House Whip Steny Hoyer all paid tribute to the Arizona congresswoman.

"The House of Representatives of America has been made proud by this extraordinary daughter of this House, who served so well during her tenure here, who felt so deeply about her constituents and cared so much for her country," Mr Hoyer said.

"Gabby, we love you. We have missed you."