Indian nuclear submarine INS Arihant successfully completed its first deterrence patrol, Prime Minister Narendra Modi said on Monday while stressing that the underwater war boat is a "fitting response" to those who indulge in "nuclear blackmail".

PM Modi congratulated the crew of the Strategic Strike Nuclear Submarine (SSBN) INS Arihant as it completed its nuclear triad achieving nuclear strike capabilities in air, land and sea.

Dhanteras, the prime minister said, has become even more special.

"India's pride, nuclear submarine INS Arihant successfully completed its first deterrence patrol! I congratulate all those involved, especially the crew of INS Arihant for this accomplishment, which will always be remembered in our history," Modi said in a series of tweets.

The development is a major achievement for the country, the prime minister said, adding that INS Arihant will help in protecting the country from external threats and contribute to the atmosphere of peace in the region.

"In an era such as this, a credible nuclear deterrence is the need of the hour. The success of INS Arihant gives a fitting response to those who indulge in nuclear blackmail," he tweeted.

The prime minister also received the crew of Strategic Strike Nuclear Submarine (SSBN) INS Arihant on Monday, a statement released by his office said.

The 6,000 tonne Arihant was built under the Advanced Technology Vessel (ATV) project at the Ship Building Centre at Visakhapatnam.

Launched on July 26, 2009 by then Prime Minister Manmohan Singh, the submarine was commissioned in August 2016 after a series of extensive sea trials.

(With Agency Inputs)