How is Brasil spelt? Is it spelled with a 'z' at the end or with an 's'?

Brazil is the correct spelling for countries where Englsih is the usual language, UK, USA, Australia etc.. or at least it is the most widely accepted BUT some people spell it with an /s/ and this is also accepted however it is not the "best" way to spell it. There is also a country discrepency as well, the portuguese spell it with an /s/ as the normal spelling for example.