The European Union backed Russia's entry to the World Trade Organisation (WTO) on Tuesday, clearing the way for Russia to join the trade body in 2011, an EU spokesman said.
"They've signed a memorandum of understanding," EU spokesman John Clancy said.
Russia, the last major world power still outside the Geneva-based world trade body, "expects to sign a protocol agreement" with EU President Herman Van Rompuy and European Commission President Jose Manuel Barroso, said Russia's ambassador to the EU, Vladimir Chizov.
"The summit is extremely important," added Kremlin diplomatic advisor Sergei Prikhodko, "as I hope we'll be able to finalise long, difficult, tiring work on questions relating to an agreement on Russia's entry into the WTO."
Moscow in October won US backing for accession to the World Trade Organisation and is looking for membership in 2011 but complains the country has negotiated longer than anyone – 17 years.
Delivering a message of reassurance on the eve of the one-day talks, EU enlargement commissioner Stefan Fuele said "we are making great strides towards the WTO accession of Russia. I am confident that the EU-Russia summit will confirm this."
The two sides struck a compromise deal ahead of the hoped-for protocol in late November, agreeing on mutual tariff cuts. But a European diplomat said unresolved problems remained, including Russian tariff hikes on European meat imports.
Overflight charges levied against European planes for the right to pass over Siberia are another sticking-point. Analysts estimate the annual royalties at up to $400 million.
Moscow has pledged to drop the levies as soon as it joins the WTO, but the EU says the issue is not linked and that Russia pledged earlier to end the Soviet-era system.
The issue of visas for Russians is also likely to come up but may not be resolved in the immediate future, with the 27-nation bloc pushing for tighter Russian border and passport controls.
Held during the Cancun climate talks and a resumption of the long-stalled Iran nuclear talks in Geneva, the two sides are also expected to address these questions.
Moscow in general has been more inclined to put the onus on its bilateral dealings with the 27 EU states rather than on signing accords with the bloc as a whole. And Russian President Dmitri Medvedev will go on to hold separate talks with Belgium on Wednesday.
"The EU is not a super-state, it's not a federation, it's still 27 countries," Chizov said.
Medvedev symbolically flies into Brussels from a historic visit to former Soviet-era satellite nation Poland, the first by a Russian head of state in nine years.
"We need to recognise that the psychological process of reconciliation following the Cold War has to run its course," said Fuele.