Prime Minister Anthony Albanese has dismissed one of Joe Biden’s latest verbal gaffes – accidentally calling Ukraine’s president “Mr Putin” – as an unfortunate “slip”.

The 81-year-old US president introduced Volodymyr Zelensky to the NATO summit in Washington with the name of his avowed enemy, drawing gasps from those in the room on Friday (AEST).

However, Albanese sympathised about the mistake, saying it happened and steered clear of stating whether Biden should step aside from the presidential race.

“Everyone from time to time, I think, has made a slip – it clearly was on his mind who President Zelensky is fighting,” Albanese told Brisbane radio station 4BC on Friday.

“But it certainly is unfortunate.”

It wasn’t the only blunder. Biden also mixed up his own Vice President, Kamala Harris, with his opponent Donald Trump — referring to her as “Vice President Trump” during his solo news conference.

During the anticipated media event, Trump mocked his adversary with a post on social media: “Great job, Joe!”

But Biden dug his heels in further, insisting he was pushing ahead with his presidential re-election bid.

He touted his decades of experience on the world stage and argued he was uniquely qualified to defeat former president Trump, 78, and lead the US for another four-year term.

“The only thing age does is creates a little bit of wisdom if you pay attention,” said Biden, who is already the oldest person to serve as US president.

Albanese said whether Biden stepped down or not was a matter for the US, but he did say the President was “on top of his game” when the pair met in Washington in 2023.

“[Biden] chaired a meeting of the entire cabinet … I had a long meeting with him in the Oval Office. We had a couple of dinners, including the official state dinner,” he said.

“He certainly was on top of international affairs, the AUKUS defence arrangements and our relationship, which is so important between Australia and the United States.”

Opposition Leader Peter Dutton said Australia’s relationship with the US would remain strong, regardless of who wins the presidential election in November.

However, there was no consensus among US Democrats about Biden’s future, Dutton said.

“When you’re speaking privately to Democrats [in Washington], I think they’re sort of equally divided about what they think the President should do,” he told Nine’s Today program on Friday.

“Ultimately, [Biden’s] the one that has to make a call, and we can work with whoever the next president is, whether it’s a second term Biden presidency or prresident Trump’s elected.”

Dutton has been in Washington as part of the Australian American Leadership Dialogue, a private diplomatic initiative that brings together Australian and American leaders.

Calls have grown for the Democrats to put up another candidate to run in November’s election against Donald Trump, following Biden’s lacklustre performance during a debate in June.

At his solo press conference on Friday, Biden coughed frequently and occasionally garbled his responses. Towards the end his answers frequently trailed off before he had completed his thoughts.

At the same time, he delivered detailed responses on issues such as the Israel-Gaza conflict and the need for western countries to produce more military weaponry to counter Russia and China.

Biden said he needed to “pace myself” a little more and complained that his aides sometimes overscheduled him.

“I’m catching hell from my wife,” he said.

The news conference gave Biden an opportunity to tout his successes on the world stage at the close of the NATO summit in Washington, where members extended support to Ukraine to combat the invasion that Russian President Vladimir Putin launched in February 2022.

The Democrat campaign has commissioned a survey to test how Harris would fare if she were to replace Biden as candidate, according to a source with knowledge of the matter. A Reuters/Ipsos poll last week found Harris would do no better than Biden in a match-up with Trump.

Prominent donors, including actor George Clooney, have called on Biden to drop out.

There are also signs that concerns are growing within Biden’s campaign operation as well. The New York Times reported that some long-time advisers were considering ways to convince him to drop his re-election bid, while NBC News reported that some campaign staffers thought he stood no chance of winning the election.

-with AAP