India's defence ministry Thursday signed off on the purchase of 33 Russian fighter jets and upgrades to 59 others worth $2.4 billion, amid rising tensions with nuclear-armed neighbour China.

The purchase of 21 MiG-29 and 12 SU-30 MKI, as well as upgrades to 59 existing MiG-29s, was to "augment" the Indian Air Force's combat squadrons, the ministry of defence said.

New and additional missile systems to be manufactured in India were also commissioned for all three branches of the military.

The beefing up of New Delhi's defence capabilities was taken due to "the need to strengthen the armed forces to protect our borders and Prime Minister Narendra Modi's call for 'Self-reliant India'", the ministry added in a statement.

The announcement followed Modi's phone call with his Russian counterpart Vladimir Putin, where he "warmly congratulated" the president after a nationwide vote on constitutional reforms that could allow him to extend his rule until 2026.

India's relationship with China has worsened in recent weeks after a border clash on June 15 that left 20 Indian soldiers dead as well as an unknown number of Chinese casualties.

Russia was New Delhi's Cold War ally and remains India's biggest armaments supplier.

In 2018, the two nations signed an accord for Moscow to supply its S-400 missile system in a deal worth $5.4 billion despite the threat of US sanctions.

India in October received the first of 36 Rafale fighter jets ordered from France in 2016 as it sought to renew its ageing fleet.