Russia has reportedly expressed an interest in supplying air-independent propulsion (AIP)-equipped submarines to the Indian Navy, if a tender is floated, a senior official from Russia’s Federal Service for Military-Technical Cooperation has said.

RIA Novosti quoted the official as saying: "The Russian side is ready to supply a foreign client with a submarine refitted to meet any requests for a different exterior and equipment, as formulated by the client."

"AIP-equipped submarines are powered by hydrogen-oxygen fuel cells."

Russian Defence Minister Sergei Shoigu and his Indian counterpart Manohar Parrikar recently agreed to fast-track a group of joint projects, which include work on a fifth-generation fighter jet that is currently being built.

India considered plans to add diesel-electric submarines to its fleet in 2007, with one of the major requirements being the addition of AIP.

AIP-equipped submarines are powered by hydrogen-oxygen fuel cells and generate less noise than conventional diesel-electric vessels. They do not have to surface or use snorkel tubes to breathe air.

The systems are currently being assessed by Russian design bureau Rubin for integration onboard the Russian Navy’s Lada-class diesel-electric submarines (Project 677) this year, followed by the construction of a new class of non-nuclear submarines powered by AIP engines in two years.