India's government on Thursday approved the purchase of 33 Russian fighter jets and upgrades to another 59 planes, acting to beef up its air force at a time when the military is locked in a border stand-off with China.

The approval for 21 MiG-29 planes and a dozen Su-30 jets will together cost 181.48 billion rupees ($2.43 billion), the defence ministry said.

The purchase, along with the upgrade of 59 other MiG-29s, was an attempt to address the “long-felt need of the Air Force to increase its fighter squadrons”, it added.

Tensions between India and China are at their highest in years following a clash last month in a disputed stretch of the border in the western Himalayas in which India lost 20 soldiers.

The two countries, which fought a brief border war in 1962, have since the recent clash moved additional forces and military equipment into key sections of the 3,488-kilometre Line of Actual Control — the ceasefire line separating the two forces.

The green light for the Russian planes followed a visit to Moscow last month by Defence Minister Rajnath Singh where he urged his hosts to speed up deliveries, officials said.

More than half of India's military hardware is still of Russian origin even though over the last decade India has turned to the United States and Israel for high-tech arms transfers. Major arms manufacturers are wooing the country as it replaces obsolete Soviet-era weapons.

The Defence Ministry also approved the purchase of air-to-air missiles developed indigenously that it said will add to the strike capability of the air force.

Rahul Bedi, a defence analyst, said the acquisition of the Russian aircraft will boost the air force's depleted fighter squadron numbers, which have dropped from an approved total of 42 to 28. One squadron comprises 18 aircraft.

He said the 21 MiG-29s will be second-hand planes that will be updated in Russia, while the 12 Su-30MKIs will be built under licence by India's state-owned Hindustan Aeronautics Ltd.