Ukraine has agreed to the modernisation of Russia's Black Sea Fleet in Crimea's Sevastopol, Ukrainian defence minister Mykhaylo Yezhel revealed.
RIA Novosti has quoted the minister as saying: "The average service life of a warship is 25-30 years. It is only natural that the current ships will be replaced, and that is the subject of negotiations."
The agreement follows as the 1997 lease accord does not allow Russia to increase the number of combat ships or modernise its weaponry at the base.
In 2010, Ukraine extended the lease of the Russian naval base in Sevastopol until 2042.
Russia is planning to induct a total of 15 new frigates and diesel-electric submarines by 2020 as per the terms of the 1997 agreeement.