I suspect you already realize how lame that statement is. The situation is not the US government forcing anyone to buy any product but European governments forcibly preventing people from selling them.
They don't want to buy
If they didn't want to buy the products, why would it be necessary for European governments to prevent people from selling them? They wouldn't need to act against the products at all if their citizens had no desire to purchase them.
How can the people know if a seed is GMO? I buy seeds and don't know if they're sterile or not.