Moyes has endured a miserable start to his reign as United have struggled to mount a strong defence of the Premier League title while also crashing out of the FA Cup in the third round.
United are 11 points behind leaders Arsenal and face a major battle just to qualify for next season’s Champions League.
There has been speculation that Moyes has been unable to win over sections of the United squad.
And the club’s struggles to maintain the level of the Alex Ferguson years has been mirrored by a drop in the value of the club’s shares on the New York Stock Exchange.
But United striker Van Persie, who has missed a large chunk of the season with a thigh injury, is certain Moyes will succeed given time.
“I think he needs time like everyone, especially if you are new at such a big club,” Van Persie told the Guardian.
“And to be fair, I don’t think people don’t understand that they have to give him a little bit more time, and I am talking about fans or even us.
“He will get that time and everyone is convinced that we will change things sooner than later.
“We lost many points this season, too many in our opinion, because if you want to go for all the trophies, you have to play better and get more wins in – but we are doing everything we can to change that.
“The manager is our leading man in that case and he is trying his best and I think he will turn things around.”