COLUMBUS - Democratic presidential candidate Martin O'Malley has failed to qualify for Ohio's primary ballot, falling short of the signatures needed to appear before the state's voters.

A spokesman for Ohio Secretary of State Jon Husted (HYOO'-sted) tells The Associated Press that O'Malley failed to get the 1,000 valid signatures needed to appear on March 15 primary ballots. The former Maryland governor's campaign submitted 1,175 signatures, but only 772 were found to be valid.

O'Malley spokeswoman Haley Morris says the campaign is exploring its options. She says O'Malley will campaign vigorously in Ohio.

O'Malley is running an underdog bid for his party's nomination against Hillary Clinton and Bernie Sanders.