Webb has trailed badly in the Democratic race, polling in the back of the pack along with former Maryland Gov. Martin O'Malley and former Rhode Island Gov. Lincoln Chafee.
Webb has raised only about $700,000 and ended the month of September with more than $300,000 in the bank. Rivals like former Secretary of State Hillary Rodham Clinton and Vermont Sen. Bernie Sanders have raised millions for the campaign.
Still, he did not rule out running for president as an independent candidate.
“I'm not going away,” he said. “I'm thinking about all my options.”
Webb surprised many fellow Democrats when he became the first major figure in the party to form a presidential exploratory committee in November.
Webb, 69, a decorated veteran of the Vietnam War, has promoted criminal justice reform and an overhaul of the campaign finance system and has been critical of the Obama administration's foreign policy. He has urged Democrats to appeal to working-class Americans and white voters in the South who have left the Democratic party in recent elections.
Webb was a Navy secretary under Republican President Ronald Reagan and an author who became a Democrat in response to the Iraq war, which he opposed.
Webb's opposition to the war, in which his son Jimmy served, was critical to his surprise Senate election in 2006 against Republican Sen. George Allen.
Webb's campaign was helped by an anti-Iraq war fervor and missteps by Allen, whose campaign imploded after he called a Democratic tracker “macaca,” an ethnic insult.
In the Senate, Webb focused on foreign affairs and veterans issues and was the driving force behind a GI Bill for post-9/11 veterans seeking to attend college after returning from Iraq or Afghanistan. He announced he would not seek re-election in 2012 and returned to writing.
Al Jazeera and the Associated Press