The U.S. Coastguard cutter Dallas, which recently delivered humanitarian aid to Georgia's Black Sea port at Batumi, will make the visit to Sevastopol, which Russia leases from Ukraine, at the invitation of Kiev.
"The ship will pay a working visit to Sevastopol on September 1. The Dallas will arrive in Sevastopol from the Georgian port of Batumi," the source said.
Tensions between Russia and the West have intensified after a build up in the Black Sea of U.S. and NATO naval vessels delivering humanitarian aid to Georgia. In an apparent response, Russia sent a group of warships, including the Moskva missile cruiser to Sukhumi, the capital of Abkhazia.
Russia's Black Sea Fleet uses the Sevastopol base under agreements signed in 1997. Ukrainian President Victor Yushchenko announced earlier this year that Ukraine would not extend the lease beyond 2017.
Yushchenko signed a decree earlier this month requiring prior notice of all movements by Russian naval vessels and aircraft from the Sevastopol base in the Crimea.
The decree is not has not yet come into force, but Russia views it as a provocation and is likely to resist any Ukrainian attempts to restrict the deployment of its navy.
