In the short term, this is unlikely to be achieved. Because bitcoin in worldwide circulation, currency of a country usually most in the country, and the government can control other currency usually need a little bit of inflation, which is conducive to economic growth, and inflation may not bitcoin.
Bitcoin as a national currency, I think many countries won't agree for that as already each country will have their own currency how can that currency replaced by the bitcoin and from bitcoin the tax is not generated to the government, So it will be a difficult task to replace it.
It is most likely to change the world's used currency which is dollar. Bitcoin is considered as a universal currency because of the fact that it is decentralized.