"All this is connected with us taking active steps, so far without shooting, to strengthen positions on the perimeter," Eduard Kokoity told a press conference.
Kokoity warned Georgia that any provocations would "end tragically for those who initiate shooting."
South Ossetia declared its independence from Georgia following the collapse of the Soviet Union in 1991. Hundreds died in the bloody conflict that followed. The pro-Western Georgian leadership has said it is determined to bring the region, along with another breakaway republic, Abkhazia, back under central control.
Tensions have been rising since Russia stepped up support for the unrecognized republics in April. Recent events have included the brief arrest of Georgian security officers by South Ossetia, small-arms fire across the conflict zone and Russian violations of Georgian airspace, as well as explosions and shootouts in Abkhazia.