India has approved plans to build two nuclear-powered attack submarines, according to two defense officials, in a project estimated to cost 450 billion rupees ($5.4 billion).

As India seeks to modernize its military in response to China’s increasing influence in the Indian Ocean, the country is focusing on strengthening its naval power and enhancing domestic weapons production.

Prime Minister Narendra Modi’s cabinet has cleared the construction of the first two submarines of a new class, out of six that the Indian Navy plans to develop. The officials, who spoke anonymously, did not provide specific timelines for delivery.

China, with a navy of over 370 ships, has become a growing security concern for India, especially after their relations deteriorated in 2020 following deadly clashes along their shared Himalayan border.

Nuclear-powered attack submarines, which are faster, quieter, and capable of staying submerged longer than conventional diesel-powered ones, are among the most formidable naval assets.

Currently, only a few nations, including China, France, Russia, and the United States, manufacture such submarines.

India, which has leased two nuclear-powered submarines from Russia in the past and returned them, is reportedly in talks with Russia to lease another one. The new submarines will be constructed at a government shipyard in Visakhapatnam, in southern India, with engineering firm Larsen and Toubro expected to be involved in the project.

These submarines will be distinct from India’s Arihant-class submarines, which are designed to carry nuclear weapons. The second Arihant-class submarine was commissioned in August.