"Russia's attachment to a relationship of understanding and cooperation with the rest of Europe is in question," French leader Nicolas Sarkozy said in the official invitation to EU heads of state and government.
"It's up to Russia to make a fundamental choice in this respect," he added.
With France holding the EU's rotating presidency, Sarkozy called the summit in Brussels so that the 27-nation bloc could formulate a "clear and united message" over Russia's conflict with Georgia.
However, the leaders will have to overcome divisions over how to deal with Russia in order to speak with one voice, with many of the ex-communist EU members plus Britain and Sweden pushing for a tough line.
British Prime Minister Gordon Brown urged on Sunday a "root and branch" review of EU relations with Russia in a hard-worded article in the Observer newspaper.
A number of the countries of "Old Europe", led by France and Germany, are eager to have a more nuanced position in order to avoid damaging ties with Russia.
Although the prospect of sanctions against Russia has been in the air, the French EU presidency has all but ruled them out, although EU leaders could decide to put negotiations on a new strategic partnership pact on hold, the AFP reports.
Poland and other eastern EU members are among the most dependent on Russian energy imports, but with fresh memories of Soviet domination, their leaders have urged a tough European stance. They are joined by Britain whose own oil and gas reserves make it less reliant on Russia.
"Over time it will feel the economic and political losses," British Foreign Secretary David Miliband said of Russia.
"If she truly wants respect and influence, and the benefits which flow from it, then Russia needs to change course," he said Wednesday.
Britain has suggested freezing Russia out of the G8 group of world powers and wants the EU to consider suspending talks scheduled to resume Sept. 15 on a major economic and political cooperation agreement with Moscow.
"We hope that it will go beyond statements and translate into action," Salome Samadashvili, Georgia's ambassador to the EU, said of the summit. "We should stop self-indulgent, wishful thinking that Russia is moving the right direction."
Georgia also wants the EU to block Russia's bid to join the World Trade Organization and threaten a boycott of the 2014 Winter Olympics in Sochi, the Russian Black Sea resort just a short drive from Georgia's disputed border, the AP reports.