Can I transfer pokemon from an American fire red to a British diamond?

I have an American Fire Red and a British Diamond but when I try to transfer my pokemon it doesn't give me the option, then when I go back into my GBA game my save file is deleted. Is this because they're not compatible? I don't see how since my DS is British and the game works fine until I play Diamond and then the file gets deleted. So is ther any way I can transfer my Pokemon?Can I transfer pokemon from an American fire red to a British diamond?
No I don't think so because migrating a american pokemon fire red to a Europe Pokemon diamond doesn't work because that it the equivalent to migrating a japanese pokemon fire red to a english pokemon diamond