Russia’s President Vladimir Putin announced new orders on Monday for more nuclear submarines to join a new, more modern Russian fleet.

Speaking on a video call, Putin greenlighted the production of new sophisticated weapon systems for the Russian Navy, including two nuclear submarines armed with intercontinental ballistic missiles, two diesel-powered submarines and a pair of corvettes. The ships would be stationed at shipyards in Severodvinsk, St. Petersburg and Komsomolsk-on-Amur, a Siberian port city in Far East Russia.

Putin’s announcement comes at a time of increased tensions at sea with the West and as part of a wider program of Russian military modernization. He made clear that it is his view that Russia “needs a powerful and well-balanced navy” and that Moscow will “continue to show the Russian flag in strategically important ocean areas.”

“We will continue to boost the potential of the Russian Navy, develop its bases and infrastructure, arm it with state-of-the-art weapons,” Putin said on the video call.

This Russian buildup at sea has been going on for years now, but the need for it has accelerated since its illegal annexation of the Crimean Peninsula from Ukraine in March 2014. In April of this year, Russian military forces massed along the Ukrainian border and conducted naval live-fire maneuvers off Crimea in parallel to NATO-Ukraine exercises called Sea Breeze 2021 finished on July 10.

On June 23, Russia claimed it fired warning shots at the British Royal Navy frigate HMS Defender when it was conducting a freedom of navigation operation near Crimea. The United Kingdom denied that Russia fired at its vessel, but a month after the incident Putin touted Moscow’s capacity to conduct an “unpreventable strike” against unspecified enemies.

"The Russian Navy today has everything it needs to guarantee the protection of our country and our national interests," Putin said on July 25.

Another reason for Putin’s trumpeting of Russia’s naval capabilities is that he may be looking to help market its weapon systems to prospective clients. This week, Russia is hosting one of its largest annual military expos called Army-2021 and it will see visitors from 92 foreign delegations in attendance. On Tuesday, Russia announced it has already concluded a new military cooperation agreement during the expo with Saudi Arabia, a traditional ally of the United States and among the largest importers of U.S. weapons.

Significantly, this year’s expo will include the first “Navy Cluster” that will showcase “all manner of weaponry, military hardware and special equipment for the benefit of the Armed Forces of the Russian Federation and on the global arms market.”