Painful moment Joe Biden introduces Ukrainian President Zelensky as 'Putin'

If US president Joe Biden was hoping that last night's display at a NATO summit would quash fears that he was no longer up to the job at his age then he'll have been sorely disappointed.

The US is just a few months away from what is expected to be one of the most important elections in its history, with Donald Trump making a third attempt for the White House.

Rather concerningly, it seems as though Trump's supporters have more of a plan for what they'll do if they get their big orange guy into power for a second term.

A conservative dominated Supreme Court has ruled that the president has immunity from the law while committing 'official acts', which is feared by some to be an attempt to vindicate Richard Nixon's belief that 'when the president does it, that means it is not illegal'.

A think tank supporting Trump has come up with something called 'Project 2025', which would put government departments under the direct control of the president and grant the ability to replace thousands of government employees with political appointees.

Joe Biden accidentally referred to Volodymyr Zelensky as 'Putin' before correcting himself. (Kevin Dietsch/Getty Images)

There's a reason why there are some concerns that the results of the next election could see the US take a more authoritarian turn, with a president essentially having legal immunity and the ability to force the government to do whatever it wants.

Now imagine those powers in the hands of Donald Trump.

As for what this has got to do with Joe Biden, since he's the sitting president he's the person most likely to contest the next election but there are serious concerns over his ability to do the job.

By the time he begins a possible second term as president Biden would be 82, and his age has been an increasing topic of discussion in the run-up to the election.

There have been a number of incidents where he has been getting names wrong, or has appeared to look less sharp than he was.

The latest of these happened last night (11 July) at a NATO summit, where he introduced Ukrainian president Volodymyr Zelensky as 'President Putin', the man currently invading Ukraine and trying to kill Zelensky, and called his own deputy Kamala Harris 'vice-president Trump' in a separate moment.

There are concerns that Biden's age has become a factor in his ability to be president, but he's said he's staying on. (Kevin Dietsch/Getty Images)

He corrected the first one, telling the summit that Zelensky was the man who would beat Putin.

It's a pair of gaffes on a night when Biden's conduct is under the microscope, and each error only means that people are looking out for further signs that he's not up to it.

Hopes that he would be alright on the night in a first election debate against Trump were dashed by a poor performance, even if Trump sounded unhinged many people focused on Biden's lack of clarity in speech, and since then the US president has been under the microscope.

Each subsequent appearance has been used as a means of judging whether or not that poor debate performance was a one-off or a sign of something worse.

There have been murmurs among Democrats that their guy should go as the party weighs up whether to stick or twist with so much on the line.

Speaking yesterday, Biden appeared to indicate that he had no intention of stepping down as the Democrat candidate, saying: "If I slow down and can’t get the job done, that’s a sign I shouldn’t be doing it. But there’s no indication of that yet."