Democratic 2020 U.S. presidential candidate and former U.S. Vice President Joe Biden departs after delivering remarks as he joined gun violence survivors and activists in Las Vegas, Nevada, U.S., February 20, 2020. REUTERS/Mike Segar

WASHINGTON (Reuters) - Former U.S. Vice President Joe Biden raised $8.9 million in January, ending the month with $7.1 million in cash, an improvement after he struggled at times last year to raise money.

Biden out-raised rival former South Bend, Indiana Mayor Pete Buttigieg, who raised $6 million during the same time, but was vastly out-raised by U.S. Senator Bernie Sanders, who raised $25 million in January.