India's first indigenously built nuclear submarine INS Arihant will begin its operations soon after extensive sea trials since 2014, local media reports said late Monday. INS Arihant was reportedly commissioned into service by Navy Chief Admiral Sunil Lanba in August. With this, India has completed its nuclear triad, making it capable of launching nuclear missiles from land, air and sea.

The 6,000-tonne vessel is the first of three such SSBNs (nuclear-powered submarines with long-range nuclear ballistic missiles) being constructed under the Advanced Technology Vessel (ATV) project at the Ship Building Centre in the port city of Visakhapatnam. The country is also constructing a second one, INS Aridhaman, and is scheduled to be delivered by 2018.

The submarine will be powered by an 83-megawatt pressurized light-water reactor with enriched uranium fuel. According to reports, the submarine is "not yet fully ready" to be deployed for "deterrent patrols" with nuclear-tipped ballistic missiles.

The INS Arihant will be armed with the recently tested K-15 Sagarika missiles with a range of 466 miles. Later, longer-range K-4 missiles — with a 2,200-mile range — developed by the Defence Research and Development Organization, will be part of the submarine.

The completion of the INS Arihant is critical for a country like India, which has a declared policy of "no first-use" of nuclear weapons.

For several months, India has been concerned over the growing presence of Chinese nuclear submarines in the Indian Ocean. In May, India and the United States agreed to lend support to each other as China stepped up its undersea activities.