NASA has given advice to Marvel after fans called on them to help Tony Stark.

The first trailer for 'Avengers: Endgame' saw Iron Man's alter ego - played by Robert Downey Jr - drifting through space after the ending to 'Infinity War' left him without the heroes turned to dust by Thanos and his own tech seemingly destroyed.

After fans jokingly asked the real life space agency for help, NASA responded on Twitter and said: ''Hey @Marvel, we heard about Tony Stark.

''As we know, the first thing you should do is listen in mission control for '@Avengers, we have a problem.'

''But if he can't communicate, then we recommend ground teams use all resources to scan the skies for your missing man.''

The character of Stark looks to be in a dire situation going into the fourth 'Avengers' movie, and co-writer Christopher Markus has confirmed fans won't know what to expect.

He said earlier this year: ''['Endgame'] doesn't do what you think it does. It is a different movie than you think it is...Also...[the deaths are] real.

''I just want to tell you it's real, and the sooner you accept that, the sooner you will be able to move on to the next stage of grief.''

His collaborator Stephen McFeely added: ''Put it this way. I think ['Infinity War'] is a fairly mature movie for a blockbuster. It's got a lot of fun in it, obviously, but boy, it gets very mature.

''The second one is also mature. We're going to own these choices, and hopefully surprise and delight you and get you invested. It's by the same studio, the same filmmaking team. They were written at the same time, shot at the same time.

''They're clearly connected, but they are definitely two different movies, one of which is dependent on what happened previous.''