LOS ANGELES — Arizona's Republican governor Jan Brewer has been left red-faced -- again -- after mistakenly endorsing President Barack Obama in a live television interview.

The hardline Republican, who famously suffered a televized "brain freeze" in 2010 -- and had a public stand-up row with Obama when he visited Arizona this year -- made the gaffe Wednesday night.

She was speaking to MSNBC after the Republican National Convention in Tampa, Florida, formally annointed Mitt Romney as its candidate to take on Obama for the White House in November.

"I know that if President Obama is elected in November, which I hope that he is, that he will be able to come together with all of us and come up with a solution," she said.

"I believe he will secure our borders and therefore we can resolve all those other issues, it's a simple matter," she added. The interviewer did not correct her, but she also referred to a "new administration" so Brewer clearly mis-spoke.

Brewer is well-known for her fierce antipathy to Obama on the issue of Arizona's controversial 2010 law which criminalized illegal immigration. The US Supreme Court in June declared most of that law unconstitutional.

In January this year she surprised onlookers when, at an airport ceremony to welcome Obama to Phoenix, she pointed her finger at the US president in what appeared to be a toe-to-toe row on the tarmac.

Afterwards White House officials explained that Obama had taken exception to a description in a book Brewer wrote of an Oval Office meeting the pair had, while Brewer said: "He was a little disturbed about my book."

Brewer infamously became lost for words during a televized debate in the run-up to 2010 mid-term elections, leaving an embarrassing silence for 10 seconds before getting back on mental track.

Afterwards she admitted she had had a "brain freeze." There was no immediate explanation for her unintended Obama endorsement.