Russia is required to comply with a month-old peace deal brokered by Sarkozy when Moscow went to war with Georgia in August over the separitist region of South Ossetia.
Four weeks after Sarkozy brokered the ceasefire deal, the West says Moscow has not honoured half of the six-point plan.
It includes pulling troops back to their pre-conflict positions.
The Russian government says a provision in the deal allowing it to conduct "special measures" permits the stationing of troops in a buffer zone around the regions of South Ossetia and Abkhazia - an interpretation Tbilisi, and the West, denies.
"We will ask Russia to apply the six-point plan scrupulously," Sarkozy told a news conference last week at the end of the EU leaders'summit, also called the European Council.
"The return of spheres of influence is unacceptable. Yalta is over," he added, referring to the 1945 major powers' meeting in the Crimea which helped shape post-World War Two Europe.
In addition to a withdrawal, Sarkozy will press Medvedev to accept more international observers to monitor the pullout.
Talks will also be organised on security arrangements in the separitist regions of South Ossetia and Abkhazia, officials said.
"It seems to us that it would be good to manage in Moscow to set a date and a place for these international discussions," an official close to Sarkozy told reporters ahead of the trip.
The talks are part of the six-point plan agreed by both sides.
The Organisation for Security and Cooperation in Europe (OSCE) said on Saturday its team of around 20 observers were now able to circulate freely throughout Georgia. It aims to send more observers soon.
EU foreign ministers meeting on Saturday approved plans for a civilian EU monitoring mission to work alongside OSCE observers in Georgia, increasing pressure on Russia to withdraw.
"The aim is clear: as big a deployment as possible so the Russians can leave as quickly as possible," one French official told reporters at a meeting of EU foreign ministers in southern France this weekend.
EU foreign ministers would not comment at the meeting on what steps the 27-nation bloc might take next against Russia.
Only a small number of states have called for sanctions so far.
"Everything will depend on what happens on Monday, Sept. 8," one senior European official said on condition of anonymity.