Minnesota Gov. Tim Walz, the Democratic vice-presidential nominee, has accelerated his preparations for his Oct. 1 debate against Sen. JD Vance (R-Ohio), participating in policy sessions and mock debates in his home state and on the road.

Democrat Tim Walz and Republican JD Vance will face off next month in the only scheduled U.S. vice presidential debate, a chance for each man to reinforce his running mate's message to voters just weeks before the Nov.