Moscow, Poti, Georgia - Russia's foreign ministry on Friday ruled out a military response to the increased US presence in the Black Sea as a US warship was due to arrive in Georgia.

The USS Mount Whitney warship is the third US vessel to dock in Georgia's Black Sea port of Poti to deliver supplies as part of a 1- billion-dollar aid package.

Russia's powerful Premier Vladimir Putin had previously threatened a military response to the build-up of NATO's naval fleet off the coast of Georgia.

Six NATO vessels, including the three US ships, now patrol those waters. The Mount Whitney was set to arrive at 1400 GMT.

While Russian Foreign Ministry official Andrei Nesterenko discounted military action, he cast doubt on the humanitarian object of the US mission.

"Such class of military ships are hardly best suited to deliver a large quantity of humanitarian aide," Nesterenko told a news conference in Moscow.

"While there are certainly holds in these ships, the provisions stored in them are usually for the crew ... Is it possible to deliver tens tons of humanitarian cargo in such a ship?" he asked.

Russian troops still man an outpost outside the Georgian port, placing Russian and US troops closest to one another since the conflict erupted in Georgia in mid-August.

Previously US ships have docked in Georgia's other Black Sea port of Batumi. (dpa)