Bitcoin, for now, is not suitable to become a national currency of any country. Bitcoin's value is too volatile so a product or service will always change in price with respect to the price of Bitcoin. Also, a transaction fee is there with every transaction, this is not practical in using in a daily basis. It will be hard for the government to control the scenario. So if a country will make Bitcoin as its national currency then they have to regulate it first.
Bitcoin is more than a national currency because in all form of currency in every country we could actually used bitcoin on transaction just consider on the acceptance of bitcoin to a specific country. But if you are going to look at bitcoin as a form of universal currency that can be used in all country with all types of transactions. So the best thing to do is to support bitcoin as a form of transaction in a daily basis that may result on further development on bitcoin price, value, transaction and security.