A US congresswoman who was shot in the head seven months ago was cheered as she cast her first vote since the attack.

Gabrielle Giffords, a Jewish Democratic Party representative for Tucson, Arizona, was in Washington to vote on the debt-limit bill, which averted a financial disaster for the US with just hours to go.

Ms Giffords was accompanied by her astronaut husband Mark Kelly.

Although she required help to walk, her presence in the chamber was a reminder of her remarkable recovery since January's shooting. The attack left six people dead and 13 others with severe injuries.

Ms Giffords said she would not have missed the vote. "I had to be here," she said. "I could not take the chance that my absence could crash our economy."

Democratic minority leader Nancy Pelosi said it was thrilling to see her back. Vice President Joe Biden added that the congresswoman was "remarkable".

"She's the embodiment of a strong, strong, strong woman," he said.