New United boss Louis van Gaal is reportedly keen on the defender who is currently on World Cup duty with Belgium.
Vermaelen has just one year left on his contract at the Emirates and despite spending most of last season on the substitutes bench, he insists he has still not made a decision over his future.
He told Sky Sports News: "I know there has been a lot of talk and a lot of rumours but the only thing I can say is that it's not true.
"Everybody understands my situation at Arsenal and that I have one year left.
"I understand that people are going to talk but I am here in Brazil and I am enjoying my time and I'm focused on what I am doing."
Vermaelen refused to be drawn on whether he has held talks with Arsenal manager Arsene Wenger about his future at the club.
He added: "We talk a lot when I am at Arsenal but it's not what I am going to discuss here, it is something you are going to have to ask him."