Huh? This is patently false. Russia did NOT annex Georgian territory. The only possible way to make this claim is if you suppose that Abhkazia is Russian Federation territory, which it is not. I can assure you that there is a border, as surely as I can assure you that Abhkazia is a REALLY crappy place.
One source . . . . Occupied territories of Georgia (Wikipedia)
https://en.wikipedia.org/wiki/Occupied_territories_of_Georgia
After the 2008 war and subsequent Russian military occupation of Abkhazia and South Ossetia, the Russian government, along with several others, considers the territories as sovereign independent states: the Republic of Abkhazia and the Republic of South Ossetia. Before Russian occupation, the unrecognized Republic of Abkhazia and the unrecognized Republic of South Ossetia did not completely control their respectively claimed territories. Russian military bases were established in Abkhazia and South Ossetia. Russia does not allow the European Union Monitoring Mission to enter either Abkhazia or South Ossetia. Russia has signed agreements with the de facto civilian administrations of both territories to integrate them militarily and economically into Russia. Russian troops have started the process of demarcation (also known as "borderization") near South Ossetia-Georgia administrative boundary line and meanwhile gradually advancing the occupation line inside Georgia to enlarge the Russian-held territory.