Tim Walz formally accepted the US Democratic Party's nomination to join the ticket with presidential candidate Kamala Harris on Wednesday, the third night of the party's convention.
"It is the honour of my life to accept your nomination for vice president of the United States," Walz said in Chicago.
"We're all here tonight for one simple, beautiful reason: We love this country."
In his speech Walz thanked US President Joe Biden for "four years of strong, historic leadership" and Harris "for putting your trust in me and for inviting me to be part of this incredible campaign."
He also drew on his time as a football coach.
"It's the fourth quarter. We're down a field goal, but we're on offense and we've got the ball. We're driving down the field, and boy do we have the right team," he said.
"Kamala Harris is tough, Kamala Harris is experienced, and Kamala Harris is ready."
Harris chose Walz as her running-mate at the start of August, shortly after Biden ended his flailing bid for re-election and passed the baton to her.
Walz, 60, has been the governor of Minnesota since 2019. US political analysts believe the former public school teacher and member of the US Army National Guard could help Harris appeal to both working-class and progressive voters in the industrial Midwest, where key battleground states are located.
Harris is set to give a major speech at the convention on Thursday night, marking the grand finale of the four-day event intended to celebrate the Democratic Party candidates and to boost their momentum for the remainder of the campaign.
She was officially confirmed as presidential candidate for the November 5 election in a purely ceremonial vote on Tuesday.
