HELSINKI -- A senior European Union official has welcomed a pledge by President Dmitry Medvedev to protect freedoms and improve the rule of law but said it remained to be seen if this would become a reality.

Days before the Slovenian EU presidency was to travel to Lithuania to try to resolve a dispute blocking talks on a new EU cooperation pact with Moscow, EU Enlargement Commissioner Olli Rehn also stressed the need for EU unity in dealing with Russia.

"In order to succeed in these negotiations, the EU must achieve greater unity first," Rehn said Thursday in a speech in Helsinki, referring to talks on a planned Partnership and Cooperation Agreement with Russia.

"Russia is a master of divide and rule," he said, "so it is up to the EU to get its act together."

Rehn noted that, while promising continuity with his predecessor, Vladimir Putin, Medvedev also emphasized freedom, the rule of law and economic liberalization when he was sworn in Wednesday.

"We welcome this approach, but are keen to see what it means in practice," he said, adding that the first opportunity to test this would be a summit with Russia in Khanty-Mansiisk on June 26 and 27.

Rehn said the European Union needed to pursue "realistic and pragmatic engagement" with Russia, given its reliance on Russian energy supplies, and that Moscow did not share core EU values of respect for democracy, rule of law and fundamental freedoms. "I don't believe we could achieve our goals with a new policy of containment, as some have suggested. Neither is there room for any policy of appeasement stemming from wishful thinking," he said.

Rehn said that while the European Union was working to increase self-sufficiency in energy and creating new import routes through southeastern Europe, 40 percent of its gas imports came from Russia and it would long remain dependent on Russian supplies.

Stressing the need for unity in dealings with Russia, he said the best results had always been achieved when the bloc presented a coherent approach.

"Our biggest shortcomings have been in areas where the common EU policies are not so strong, such as energy security," he said.

Slovenian Foreign Minister Dimitrij Rupel will travel to Vilnius on Monday after EU foreign ministers failed two weeks ago to agree on a mandate for talks with Russia because of Lithuanian objections.

Lithuania is demanding assurances on Russian energy supplies, judicial cooperation and policy on frozen conflicts in breakaway areas in other former Soviet republics, notably Georgia and Moldova.

In Warsaw, a Polish diplomat said Friday that Lithuania was likely to lift its veto on talks by the end of this month.

n British Prime Minister Gordon Brown phoned Medvedev on Sunday to offer his congratulations after a period of strained ties, Bloomberg reported.

The two leaders discussed "intensified" economic cooperation and agreed to meet on the sidelines of the Group of Eight summit in Japan in July, the Kremlin said.