US Vice President Mike Pence on Wednesday cast the re-election of President Donald Trump as critical to preserving law and order and economic viability, warning Democratic rival Joe Biden was a stalking horse for the radical left.

Amid widening protests over the police shooting of Jacob Blake, a black man, in Wisconsin, Pence and other Republicans at their national convention described the Nov 3 election between Trump and Biden as a choice between law-and-order and lawlessness.

"The hard truth is you won't be safe in Joe Biden's America," Pence said in a speech that capped the convention's third night.

Police in Kenosha, Wisconsin, shot Blake, 29, multiple times in the back at...