Donald Trump's campaign and its joint fundraising arm with the Republican Party raised about $90 million in August, the campaign announced Thursday.
It said the campaign and joint fundraising committees ended the month with $97 million on hand. However, it did not detail how the money is split between the campaign and the party, an important distinction. The campaign will likely offer more detail in a report to the Federal Election Commission due Sept. 20.
Trump's Democratic opponent Hillary Clinton raised more than $140 million for her campaign and the party in August. Her campaign said she ended the month with about $68 million on hand.
Steven Mnuchin, the Trump campaign's national finance chairman, downplayed the fundraising gap, saying the campaign focused on meeting with voters in August rather than attending fundraisers.
"We run a very efficient organization. We don't need to raise nearly as much as Clinton, who needs the money to support her negative advertising," he told CNBC in a phone interview.
For comparison, the Trump campaign said it and the GOP raised $80 million in July, but it reported receipts of only $36.7 million in the FEC report. The campaign ended July with $38.4 million on hand.
Trump's camp said he made another "significant contribution" in August, bringing his total funding for the campaign to nearly $60 million. He had contributed about $52 million of his own money by the end of July, meaning about $8 million came from his own pocket in August, according to NBC News.
Clinton has consistently outraised and outspent Trump, but the race has grown tighter in recent weeks. Clinton's lead has fallen to less than 3 percent in an average of recent polls, according to Real Clear Politics.
Trump's campaign began seriously fundraising in June and only recently started purchasing expensive television ads. Much of its spending has gone to a San Antonio company that handles digital fundraising and marketing efforts.
— CNBC's Lori Ann Larocco contributed to this report