Some Republicans expressed concern that discouraging mail-in voting could reduce turnout among rural conservative voters. (EPA Images pic)

WASHINGTON: President Donald Trump encouraged supporters on Saturday and again on Monday to vote by mail if they wanted, a change of tone for the US president, who has for years described mail-in voting as a practice rife with fraud.

Speaking to reporters at the White House before departing for a rally in Nebraska on Monday afternoon, Trump said his supporters could vote by mail in the coming congressional midterm elections on Nov 3, even as he said he preferred in-person voting.

"They can vote by mail if they want, because we seem to have no choice because a lot of people want to vote by mail, but a lot of very good people also want to vote in-person," Trump said. "You can do either."