Joe Biden raised $15.2 million in the past three months, his campaign announced Thursday, leaving the former vice president $10 million behind U.S. Sen. Bernie Sanders in third-quarter contributions

Biden’s third-quarter fundraising also falls $6 million short of the $21.5 million he brought in during the second quarter.

Still, campaign manager Greg Schultz said in a statement, “Today’s fundraising totals put the campaign in a strong position as we enter the fall. The question any campaign faces at this point is whether or not you have the resources to compete in early states and sustain your efforts beyond. Our campaign unequivocally does and builds on our strength each week.”

Biden’s campaign said 98% of his contributions came from grassroots donors of less than or equal to $200, with an average donation of $44.

The campaign on Thursday also announced a $6 million television and digital ad buy in the early states. Schultz said the campaign is “investing heavily in our field operations, where we have well over 200 staff and dozens of field offices open with more to come through the fall and winter.”

“We will continue executing on our broader strategy to build support and reach voters to make Joe Biden the Democratic nominee next summer, and beat Donald Trump like a drum next November,” he added.

Biden, the long-time front-runner who now has U.S. Sen. Elizabeth Warren nipping at his heels — and in some cases surpassing him — in the polls. He’s also being blasted by President Trump and his allies over his and his son’s involvement in Ukraine, as the president seeks to fend off Democrats’ impeachment inquiry against him.

“I’m not going to let him get away with this. I’m not backing down,” Biden said in Nevada Wednesday.

Sanders raised the most on the Democratic side in past three months with his $25.3 million haul, the highest of any Democratic presidential hopeful per quarter thus far. South Bend, Ind., Mayor Pete Buttigieg raised $19.1 million, U.S. Sen. Kamala Harris earned $11.6 million, entrepreneur Andrew Yang posted $10 million and U.S. Sen. Cory Booker brought in about $6 million — $2 million of which came after his campaign pleaded with supporters to pitch in to keep him in the race. Author Marianne Williamson announced she raised $3 million, and U.S. Sen. Michael Bennet said he raised $2.1 million.