For any reason, or in fact no reason, a sovereign state doesn't need to actually provide justification to refuse entry. They have the right to refuse foreign citizens from entering the country. I mean, when I cross the border into the United States, if the U.S. border service says I can't come in, I don't have a right to appeal. I have to accept that decision.
On October 26th, 2006. See this statement in context.