Both submarines are improvements over their original projects, and many more are expected to enter service by 2021.

Two nuclear-powered submarines — Kazan and Knyaz (Prince) Vladimir — will join Russian Navy before the end of the year, Russian Defense Minister Sergei Shoigu said Tuesday. Russian Embassy in the United States posted a video showing the upcoming ships in its Twitter account.

Speaking at a meeting in Severodvinsk, Shoigu said that the new submarines will "define the future image of [Russian] submarine navy; allow to increase the defensive potential and strengthen Russia's positions in the World Ocean."

​Kazan's construction started ten years ago, in 2009. The submarine has been launched in 2017, and undergoes tests now. Prince Vladimir's construction began in 2012, the submarine has also been launched in 2017.

​Both submarines are modernized versions of their projects — 885 and 955, correspondingly. So far, there is only one Project 885 boat, K-560 Severodvinsk. There are three Project 955 submarines in service.

​​While Kazan is armed with Kalibr and Oniks cruise missiles, Prince Vladimir carries RSM-56 Bulava nuclear missiles, also known as SS-NX-30 under NATO designation.

Five more Project 885 boats and four more Project 955 submarines are expected to join the Navy by 2021.Source: sputniknews.com