The Yury Dolgoruky will enter service in June and the Alexander Nevsky in August, he said.

The Borey-class subs will be armed with Bulava intercontinental ballistic missiles but Serdyukov did not say exactly when the troubled missile will enter service.

The Yury Dolgoruky’s construction began in 1996 at the Sevmash shipyard and was completed in 2008. It has a crew of 130 and will be armed with 16 Bulava SLBMs and six SS-N-15 cruise missiles.

President Dmitry Medvedev said in late December that the flight tests of the Bulava SLBM were completed and it will now be adopted for service with the Russian Navy.

Russia successfully test launched two Bulava missiles on December 23.

They were the 18th and 19th test launches of the troubled Bulava. Only 11 launches have been officially declared successful.

But some analysts suggest that in reality the number of failures is considerably larger. Russian military expert Pavel Felgenhauer said that of the Bulava's first 12 test launches, only one was entirely successful.

Despite several previous failures officially blamed on manufacturing faults, the Russian military has insisted that there is no alternative to the Bulava.

The Bulava (SS-NX-30) SLBM, developed by the Moscow Institute of Thermal Technology (since 1998), carries up to 10 MIRV warheads and has a range of over 8,000 kilometers (5,000 miles). The three-stage ballistic missile is designed for deployment on Borey-class nuclear submarines.