Warsaw  - Polish Prime Minister Donald Tusk met Tuesday with central bankers to plan the country's euro adoption, amid doubts Warsaw can maintain the strict economic criteria to join the 15-nation euro zone.

Tusk insisted Poland would meet the economic criteria for membership in 2011, and added a detailed schedule for entry will be prepared in October.

"The government, the Monetary Policy Council and the National Bank of Poland are ready for close cooperation to achieve this aim," Tusk said after the meeting.

Tusk's recent bold announcement that Poland would adopt the currency by 2011 got support from business and ordinary Poles, but others raised doubts over whether Poland could attain in time the European Union's benchmarks on inflation, budget deficit and national debt.

Tusk's 2011 target date was the most concrete promise of joining the euro zone since he took office in November. He called the goal "difficult but possible," and said a recently-drafted budget - which cuts deficit nearly by half - would lend the plan credibility amid long-time criticism from the EU on Poland's deficit.

Critics called the deadline unrealistic, saying Poland must maintain a stable course for two years before it can enter the euro zone and meet other fiscal and inflation criteria for at least a year before entry.

Many pointed out the Polish constitution would have to be amended, as the Polish National Bank currently has sole power to distribute money. Rewriting the constitution would require support from the opposition Law and Justice, which is eurosceptic.

Poland agreed to adopt the euro as part of its deal to enter the EU in 2004 along with eight other ex-communist nations, but Warsaw had previously been reluctant to set a deadline.

Slovakia plans on January 1 to become the first former Soviet-bloc nation to adopt the euro, beating out Poland and others like Hungary and Czech Republic. (dpa)