WASHINGTON - The former Republican governor of Massachusetts Bill Weld formally announced his candidacy for the US presidency on Monday, becoming the first Republican to challenge President Donald Trump in the 2020 race.

"The voices of the American people are being ignored and our nation is suffering," Weld, said in a statement. "It is time to return to the principles of Lincoln - equality, dignity, and opportunity for all."

Weld, who formed an exploratory committee in February, was known for his fiscally conservative, socially moderate agenda as a Republican governor in Massachusetts from 1991 to 1997 and has been a fierce critic of the Trump White House.

"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," Weld told CNN.

The 73-year-old recently rejoined the Republican Party after spending several years as a Libertarian.

A graduate of Harvard College and Harvard Law School, Weld ran for Senate in Massachusetts in 1996 but lost to John Kerry. He later moved to New York and in 2005 unsuccessfully sought the Republican nomination for governor.

Other Republicans who are reportedly considering a primary bid against Trump are former Ohio Governor John Kasich and Maryland Governor Larry Hogan.