WASHINGTON (REUTERS) - Democratic presidential candidate Joe Biden was expected to report a record fund-raising haul of more than US$300 million (S$400 million) for the month of August, the New York Times reported on Tuesday (Sept 1), citing two people familiar with the matter.

Biden, who is leading Republican incumbent President Donald Trump in most national opinion polls ahead of the Nov 3 election, raised US$140 million in July.

The campaign was expected to see a boost from the Democratic National Convention and the naming of his vice presidential pick, US Senator Kamala Harris of California, in August.

Biden and closely allied groups raised US$70 million during the party convention, which was held virtually from Aug 17 to Aug 20, the campaign previously announced.

Trump's campaign, which brought in US$165 million in July, has not announced how much it raised in August.

The Times said its sources did not know what the final figure for August would be, but the reported number would likely be the most ever raised by a US presidential candidate in a month.

The Times did not name its sources.

A Biden campaign spokesman said the campaign would not confirm the fund-raising haul for August on Tuesday and that they were still finalising the exact number raised.