Sebastian Stan says it has been "really hard" shooting 'Avengers: Infinity War' and 'Avengers 4' because of the schedule.

Sebastian Stan

Sebastian Stan

The 35-year-old actor stars as Bucky aka The Winter Soldier in the Marvel Cinematic Universe and will reprise his role in the upcoming two movies, but admitted the filming process has felt "a little bit out of sync".

Speaking at Rhode Island Comic Con, Stan said: "It's not something you always deal with. I feel like you always kind of have a script. But I guess, what I would say is, because we've done these characters for a bit now, there's a little bit of a telepathic kind of knowledge between us and the writers. And you kind of can sometimes guess where they're going to take it, a little bit. For example, this one was really hard, because we keep going in and out. I go back there for a week, and then I leave for a month. And then I go back there for a few more days. So it's a little bit out of sync. But it still hopefully adds up in the end. Almost every scene is epic."

'Avengers: Infinity War' will see the hero squad - Iron Man (Robert Downey Jr.), Captain America (Chris Evans), Thor (Chris Hemsworth), The Hulk (Mark Ruffalo), Scarlet Witch (Elizabeth Olsen), Vision (Paul Bettany), Black Widow (Scarlett Johansson) and Hawkeye (Jeremy Renner) - join forces with the Guardians of the Galaxy to save the Earth.

The two teams will have to work together to fight intergalactic tyrant Thanos, with some help from newcomers Spider-Man (Tom Holland), Black Panther (Chadwick Boseman) and the screen debut of Captain Marvel (Brie Larson).

Stan isn't the only member of the cast who finds shooting the 'Avengers' movies tough, after Karen Gillan - who stars as Nebula in the 'Guardians of the Galaxy' franchise - admitted that her latest on-set experience of working with directors Joe and Anthony Russo has been an exhausting process.

She shared: "So this is the longest shoot in the world. It's been going since January, and it goes right up until December. And then it goes into re-shoots - like immediate, more additional photography - next year. So it's like an ongoing thing, which is really cool, because it feels like a whole family now."