Actor Goran Visnjic is on the fast-track to becoming an American citizen after sailing through his recent naturalisation test.

The Croatia-born star has been living in the U.S. for over a decade and decided to make it his permanent home - and now he's in the process of becoming a citizen.

And he admits he found the test to be a little simple in parts.

The former E.R. star says, "I did take the test and I did pretty well... Some questions, you're not quite sure of - they're trick questions... The question is like, 'Which ocean is on the west side of the United States...?' (and I'm thinking), 'If I say Pacific it's probably wrong, it must be something else.'"