FIFA has introduced emergency measures to stop soccer players taking advantage of the governing body's regulations to switch nationalities.
Following a decision by FIFA's Emergency Committee, any player who assumes a new nationality without having a clear connection to that country will not be eligible to play for the national team.
FIFA said on Wednesday players would now have to show strong links with their adopted country through their parents or grandparents, or show they have lived there for two years, to be able to play for the national team.
Qatar said last week it would naturalise three Brazilians to bolster their team ahead of qualifiers for the 2006 World Cup but following FIFA's announcement the Qatar Football Association (QFA) put the moves on hold.
The QFA was set to offer Qatari citizenship to Werder Bremen striker Ailton and brothers Dede and Leandro of Borussia Dortmund. The trio have no previous link with Qatar.
"Naturalisation that allows players with no obvious connection to the new country to play for that country's national teams is not the aim and object of the statutes," FIFA president Sepp Blatter said in a statement.
"For that reason, we have to put an immediate stop to such practices. I will also bring this matter up at the ordinary FIFA congress in Paris on 20-21 May 2004 with the aim of amending our statutes accordingly."
The relevant FIFA statute opens the door for players who have not played for their original country to assume another nationality and play for that country's team.