Speaking in French, Milinkevich said, "Lukashenka is no longer the president of a country. He is a citizen who has power that is not legitimate."
The EU has backed the Belarusian opposition in denouncing the March 19 presidential election as fraudulent.
EU lawmakers, in a non-binding resolution, called on European governments not to recognize Lukashenka as president.
EU leaders meeting in Luxembourg on April 10-11 are expected to consider restrictive measures against Belarusian officials.
The Belarusian Foreign Ministry today dismissed the EU criticism as "laughable."
Yushchenko (center) with Russian Ambassador to Ukraine Viktor Chernomyrdin (left), Russian Foreign Minister Sergei Lavrov (rear), and Russian President Vladimir Putin (AFP file photo)
IN WHOSE ORBIT? Just over a year ago, tens of thousands of Ukrainians led an extended public uprising that toppled the country's entrenched, pro-Russia regime. But the country remains deeply divided between the east, where ethnic Russians look toward Moscow, and the west, which yearns for deeper integration with Europe. Can Ukraine elect a legislature that represents this torn country? (more)