Tim Kaine

The Indiana governor delivered a smooth performance at Tuesday's vice presidential debate, lobbing attacks at Hillary Clinton with far greater effect than Trump in last week's showdown. Facing a feisty Tim Kaine, whose debate appearance will likely be remembered for his aggressive interruptions, Pence was calm and refused to be baited.

"Bienvenidos a todos," the Virginia senator said, a phrase that translates to "welcome to everyone."

Clinton and Kaine's first joint appearance as running mates at a campaign rally here marked the official unveiling of the Democratic ticket. The duo will face off against Republican presidential nominee Donald Trump and his running mate, Indiana Gov. Mike Pence.

At a rally in Miami, Mrs Clinton reeled off the Virginia senator's career achievements, including his work decades ago as a civil rights lawyer and time spent with missionaries in Central America, to depict him as a man dedicated to social justice.

"Senator Tim Kaine is everything Donald Trump and Mike Pence are not," Mrs Clinton said to a roar of approval from the crowd.

"He is qualified to step into this job and lead on day one," she added, praising his work as governor of the key swing state of Virginia and his record of shepherding it through hard financial times.

Mrs Clinton broke the news in a tweet late on Friday. She plans a formal announcement on Saturday.

Mrs Clinton passed over more left-leaning candidates in favour of the 58-year-old senator, who is a strong supporter of free-trade agreements.

His home state of Virginia is a major battleground in the coming election.

Who is Tim Kaine?

Mr Kaine speaks fluent Spanish and could help the Clinton campaign maintain its support among Hispanic Americans - a growing voting bloc.