"Work on the agreement is coming to a close, the document will soon be ready and it will be signed in the nearest time," Abkhaz leader Sergei Bagapsh told the Interfax news agency.
"This document stipulates the stationing of the Russian base in the Gudauta district of Abkhazia for a term of 49 years," he added.
Bagapsh did not give further details but he said earlier this year that the two sides had reached an agreement in principle for the creation of a base for ships of the Russian Black Sea Fleet in the Abkhaz port of Ochamchire.
Russia’s plans to keep thousands of troops in Abkhazia and Georgia’s other breakaway region of South Ossetia have angered Tbilisi and its Western allies, who say it violates the ceasefire that ended the Russia-Georgia war last August.
Russia poured troops and tanks into its southern neighbour to push back Georgia’s military attempt to regain control of South Ossetia, and Moscow subsequently recognised Abkhazia and South Ossetia as independent states.