Poland originally planned to adopt the euro in 2012. However, its weakening currency, the zloty, and the fallout from the global economic crisis forced a delay, even though Poland's economy _ unlike others in the EU _ is still growing.

Poland will probably join a pre-euro currency program, the so-called ERM-II, in about two years' time, said Witold Kozinski, the deputy governor of the National Bank of Poland.

That system demands low and controlled inflation, healthy public finances and a budget deficit below 3 percent of gross domestic product for two years prior to the adoption of the euro.

"Poland should join the euro zone as a well-organized and efficient country," Kozinski said.

Adopting the euro will be possible in 2014 or 2015, at an exchange rate close to 4 zlotys to the euro, he added.

A euro currently buys 4.20 zlotys.

Of the 10 formerly communist countries that have joined the EU in recent years, Poland is by far the most populous and has the biggest economy. Its adoption of the euro would expand the currency to another 38 million people.