WASHINGTON (AFP) - President Donald Trump said on Tuesday (Aug 11) that some men may feel "insulted" by his Democratic rival Joe Biden's committment to choose a woman as his vice-presidential candidate.

"He roped himself into a certain group of people," Mr Trump told Fox Sports Radio in an early morning phone-in interview.

"Some people would say men are insulted by that and some people would say it is fine," Mr Trump said.

Declaring that he wants a government as diverse as the country itself, Mr Biden committed early in his campaign, in March, that he would name a woman on the ticket.

He is expected to announce his choice this week.

Only two other women have been nominated vice-presidential candidates - Ms Sarah Palin by the Republican party in 2008 and Ms Geraldine Ferraro by the Democrats in 1984 - and neither made it into the White House.

No woman has won the presidency either.

In the radio interview, Mr Trump praised his own vice-president, Mr Mike Pence, but said bluntly: "people don't vote for the vice-president, they really don't."

"You can pick a George Washington to be a vice-president. Let's pick up Abraham Lincoln, coming back from the dead. They just don't seem to vote for the vice-president."