After meeting with President Bronislaw Komorowski at the presidential palace, Obama said: "Poland, because of its extraordinary success, both as a democracy and as a market-based economy, is a model and example for the region.
"The incredible transformation that's taken place over the last 25 years here in Poland is now making it a leader in Europe," Obama said.
In remarks after their meeting, both Obama and Komorowski mentioned neighboring Belarus, where a recent government crackdown has included harassment of Polish journalists.
"Belarus is backsliding, and it's important that we work together, as we've already committed to doing, to encouraging civil society, encouraging reformist trends within Belarus," Obama said.
Later, during a joint news conference with Obama, Prime Minister Donald Tusk said: "There is no future for such dictatorships as the one which is represented today by [Alexander] Lukashenko in Belarus."
Tusk and Obama announced cooperation on "clean energy" development of shale oil and nuclear power and reaffirmed their NATO alliance, including the deployment of missile defense in Poland.
Obama also congratulated his host nation on assuming the presidency of the European Union for the first time.
The president, who began his European trip by visiting his mother's ancestral village in Ireland, also said, "In some ways I am part of Poland because I come from Chicago, and if you live in Chicago and you haven't become a little bit Polish, then something's wrong with you."
On Sunday Obama travels to Joplin, Mo., to meet with victims of last week's devastating tornadoes.