New Manchester United striker Anthony Martial says he is unconcerned by his £36 million price tag as his record fee continues to make waves in his native France.

Martial, 19, joined United from Monaco on Monday as he became the most expensive teenager in football's history.

After returning to the French national team's headquarters on Tuesday after his brief trip to Old Trafford, Martial said he cannot wait to get started.

"It was a restless night," he said in a video interview posted on the French Football Federation's website. "I'm very happy to sign for Manchester United. It's a very big club and I hope I'll be able to show all my qualities.

"There's certainly been a lot of talk about it [the transfer] but the most important thing will be on the pitch and to show people who I am.

"Football is football -- it's changed nothing. You have to stay true to yourself and keep your head on your shoulders."

Anthony Martial sealed his move to Manchester United on Monday. John Peters/Man Utd via Getty Images

L'Equipe reported on Tuesday that, when bonuses are included, the deal for Martial could eventually be worth €80m, which would make him the most expensive French player in history.

But, having scored 15 goals in 70 appearances for Monaco, Martial insists he is not concerning himself with his record-breaking price tag.

"I don't know if I'm worth €80 million but I don't worry about the sums," he said.

"I'm going there for the football side of things, the price is between the two clubs and I don't see myself under any pressure.

"My family were really happy for me that I'm going to such a big club as Manchester United. They were definitely a bit nervous given my high price but I'm going to stay focused on proving my worth."

Former Chelsea defender Frank Leboeuf, a World Cup winner with France in 1998, was critical of the fee, saying it showed there were no limits and that it was impossible to tell a player's worth anymore.

"It's becoming indecent in a time of economic crisis," Leboeuf told RMC. "I'm not the last Samaritan -- I think money is needed in football but you can't do whatever you want with it.

"It means that if Martial is sold for €80m then Barcelona could ask for €1 billion for Messi. Between the experience he has and what he's already proven, there's no longer a price for a player like him.

"You have to remain reasonable. I genuinely think that money has a value and it seems to me that some clubs have forgotten it."