Wilmer Valderrama has praised his former girlfriend Demi Lovato as a ''hero''.

The 'NCIS' showed his support for his 25-year-old ex after she performed her song 'Skyscraper' at a March For Our Lives rally in Washington DC over the weekend.

He told Entertainment Tonight: ''She's a hero. She's a hero to young men and women out there. I think that she's literally the image of recovery and getting their life together, so I'm excited that she's there and for this historic moment for young people too.''

And Wilmer, 38, praised his fellow Hollywood stars for getting involved in the student-led demonstrations, which were set up after 17 deaths in a school shooting in Parkland, Florida, last month.

He said: ''They used to tell us when we were young and entering the industry, 'Oh you're an actor, don't get involved in politics.'

''But then you see that politics affect policy and policy affects humankind. It's really interesting as citizens, as people in general, that you actually get involved. So I think that's why it's exciting to see that so many people are lending their voices, but most importantly, their platform for other people's voices, because we gotta just be amplifying the people's word and the people's spirit.''

And Wilmer, who was involved with the marches, revealed he grew up with gun violence in his native Venezuela.

He said: ''I grew up in Venezuela and you grow up with a reality - [on] the six o'clock news, you're talking about machine guns and you're talking about hits. It's a rude awakening when you wake up to that reality, specifically, you're nine, 10, 11 years old in Venezuela knowing that this is normal to you.

''And coming to the United States, a land that has allowed us to have the freedom to become anything we can be...We shouldn't have to worry about that while we're dreaming out loud.''