Justin Timberlake and Jessica Biel are ''devoted'' to their relationship.

The 36-year-old actress has been married to the 'Can't Stop the Feeling' hitmaker since 2012 and has three-year-old son Silas with him but, although their busy globe-trotting careers often separate them, they believe their marriage is solid because they work hard to keep the peace and understand one another.

Speaking on 'Today', the brunette beauty said: ''We're lucky enough to go and stay in different places and live in different places while we work and that's definitely part [of having a strong marriage].

''But, honestly, I just really feel like you have to work hard. That doesn't change if you work at home or in an office or you're on a tour. It doesn't change, the work doesn't change. Being devoted to the relationship is our biggest priority.''

The couple have just returned to the US after spending a bit of time in Europe - visiting Paris, London and Copenhagen - with their son.

She explained: ''It is fun to be on the road.

''You feel like a wild group of gypsies and you're all in this together. You're seeing so many new places and I think it's amazing for our son because he's hearing new languages. We're talking about different countries, the names of different countries, what he likes, what he's seen. He would never have these experiences if we didn't just get out there and go for it.''

And, although they try to make time for date nights while Justin is on the road touring, Jessica has admitted they tend to opt for cosy time in the hotel room.

She explained: ''Yes, we're in these amazing places, but a lot of times we're trying to protect his immunity and protect his body from breaking down.

''A date night for us would be just sitting in the hotel and having room service and watching a movie -- just like everybody else.''