President Donald Trump has raised more than USD 100 million for his re-election battle in 2020, giving him a huge financial advantage over many potential Democratic contenders jockeying to challenge him, US media reports on Tuesday.

The President raised over USD 18 million during the July-to-September fundraising quarter through his campaign committee and the joint fundraising operations he maintains with the Republican National Committee, according to his campaign and filings on Monday with Federal Election Commission.

That haul means Trump's re-election effort's war chest now exceeds USD 106 million, CNN reported.

Trump's campaign ended last month with more USD 35.4 million in available cash stockpiled in its bank account.

Trump, who has challenged most political rules since launching his unorthodox 2016 presidential campaign, took the unusual step of filing for re-election the day he was sworn in to office in 2017.

The 72-year-old US president began holding campaign-style rallies in the first months of his presidency.

By contrast, Barack Obama waited until the third year of his presidency to begin fundraising in earnest.

Donors who give in small amounts helped fill the businessman-turned-politician's campaign accounts.

Small-dollar contributions of USD 200 or less represent nearly 98 per cent of the money he collected during the third quarter of the year, campaign officials said.

"After twenty months in office with unparalleled results for peace and prosperity in America, President Trump has provided the results he promised," Lara Trump, Trump's daughter-in-law and a senior campaign adviser, said in a statement.

"And grassroots America has responded to these remarkable results and the booming Trump economy with their generous support of our campaign."

She encouraged the president's supporters to turn out for next month's mid-term elections so that Trump "can continue to build on his agenda."