Bill Weld: Trump to face 2020 Republican challenge

US President Donald Trump is facing a longshot challenge from within his own party ahead of next year's White House election.

Former Massachusetts Governor Bill Weld has become the first Republican to challenge Mr Trump in 2020.

Mr Weld, 73, has released a campaign video contrasting his style with the current president's.

But he faces an uphill battle to take over a Republican party that has been refashioned in Mr Trump's image.

Mr Weld was governor of Massachusetts from 1991-97 after serving in the justice department under President Ronald Reagan.

He was running mate on the Libertarian ticket during the 2016 presidential election.

"I really think if we have six more years of the same stuff we've had out of the White House the last two years that would be a political tragedy," he said on CNN.

"So I would be ashamed of myself if I didn't raise my hand and run."

Mr Weld's campaign video touts his cross-party credentials as a Republican who was elected in the Democratic stronghold of Massachusetts.

The three-minute production contrasts his record with clips of provocative statements by Mr Trump.