In the US, something like that would probably be considered a "true threat", and that's one of the well-known and uncontroversial exceptions to the First Amendment's protections for freedom of speech.
Sorry, but no. It has to be a "credible threat", naming a specific action, a subjective and objective intent, as well as some indication that the person actually has the means and opportunity to carry it out. The "if we ever meet" part of the statement is a clear indication that the threat is not actually a credible one. There's a good discussion of the issues over at the PopeHat.