China and India, the world's two most populous nations, are intense rivals and have accused each other of trying to seize territory along their unofficial divide, known as the Line of Actual Control.

However, Chinese President Xi Jinping and Indian Prime Minister Narendra Modi met on the sidelines of a BRICS gathering in Russia on October 23, the pair's first formal meeting in five years.

In their meeting, Xi said they should "strengthen communication and cooperation", while Modi said "mutual trust" will guide ties with China.

It signalled a potential thaw between the nuclear-armed neighbours since clashes between their troops in 2020 over their border, which killed at least 20 Indian and four Chinese soldiers.

On Thursday, photographs released by the Indian army showed soldiers shaking hands and handing gift-wrapped boxes of sweets in the rugged icy mountains of Ladakh and Arunachal Pradesh, to mark India's Hindu festival of lights, Diwali.

After the 2020 clashes, more than 20 rounds of military talks were held.

Both sides pulled back tens of thousands of troops and agreed not to send patrols into a narrow dividing strip.

But two major points remained with troops and tanks on both sides staring at each other.

On October 21, days before Xi and Modi met, a deal was struck to pull back a few hundred soldiers deployed at forward positions, a term dubbed "disengagement", and resume military patrols.

An Indian army official who was not authorised to speak to journalists confirmed that "sweets were exchanged between troops of India and China at several border points on the occasion of Diwali".

Rajnath Singh, India's defence minister, said Thursday that New Delhi's "efforts will be to move the matter beyond disengagement", but added that that "will have to wait a little longer", the Press Trust of India news agency quoted him as saying.

India is wary of its northern neighbour, and disputes over their 3,500-kilometre (2,200-mile) frontier have been a perennial source of tension.

China claims all of India's northeastern state of Arunachal Pradesh, considering it part of Tibet, and the two fought a border war in 1962.