The Baltic nations of Estonia, Latvia and Lithuania will all be members of the Organisation for Economic Cooperation and Development by 2018, the group's head said on Friday.
"Latvia is now in the process, Lithuania is going to have the decision taken next May or June, which we're sure will be positive," OECD secretary general Angel Gurria said in a lecture at the Stockholm School of Economics in Riga.
With Estonia already a member of the group comprising 34 leading world economies, "eventually in 2017-8 we'll have the three Baltic (states) as full members of the OECD", he said.
Gurria, a former Mexican finance minister who has headed the OECD for eight years, added that it was "an ambitious but realistic calendar".
The Baltic trio was hit hard by the global financial crisis in 2008 but bounced back after applying deep austerity measures. They now boast among the best growth rates in the European Union.
Estonia and Latvia joined the eurozone in 2011 and 2014 respectively and Lithuania is set to adopt the single currency on January 1.