Despite that, Lithuania, which last month took over the European Union’s rotating presidency, is doing everything possible to draw these countries closer to Europe. Vilnius has invited the six countries to an Eastern Partnership summit meeting next November.

For Lithuania, and its neighbor Poland, which has pushed hard for a closer relationship between the European Union and the Eastern Partnership countries, the crowning moment of the summit meeting would be the signing of an association agreement between the European Union and Ukraine, the Eastern Partnership’s biggest member.

Such an agreement would bring economic and political advantages to both sides. It would also encourage Ukraine’s reformers and pro-Western political movements to pursue the modernization of its economy and strengthen the rule of law.

The association agreement with Ukraine is “not just technical negotiations with just another partner; it is a geopolitical process,” said Lithuania’s foreign minister, Linas A. Linkevicius.

The European Union and Ukraine initialed the agreement more than a year ago, but it has not been signed. Ukraine still has to introduce more reforms.

The German government has been the most vocal in insisting that Ukraine release from prison the former prime minister Yulia V. Tymoshenko, who is ill. She was sentenced in 2011 for abuse of office. On a visit to Ukraine last June, Foreign Minister Guido Westerwelle of Germany said that Ms. Tymoshenko had not been given a fair trial. He offered to transfer her to Germany for medical help.

“Mrs. Tymoshenko, in our opinion, has the right to a fair trial and appropriate medical assistance,” Mr. Westerwelle said. Germany was expected to veto signing the association agreement unless Ukraine introduced reforms that included dealing fairly with political detainees like Ms. Tymoshenko.