China's military on Friday named four soldiers killed in a brawl with Indian forces last year, the first confirmation of deaths by Beijing from the border clash that also killed at least 20 Indian soldiers.

The Chinese soldiers "sacrificed themselves" during the June confrontation in the contested Galwan Valley border area with an unnamed "foreign military", the defence ministry said.

India and China fought a border war in 1962 and have long accused each other of seeking to cross their frontier -- which has never been properly agreed -- in India's Ladakh region, just opposite Tibet.

In mid-June, 20 Indian soldiers were killed in a brutal, high-altitude border battle in the Galwan valley in one of the deadliest clashes between the two sides in recent decades.

Beijing at the time acknowledged that the clash had resulted in casualties but did not confirm if any Chinese soldiers died.

Battalion commander Chen Hongjun and three other soldiers have been given posthumous awards, the defence ministry said.

It blamed the battle in June on "foreign troops blatantly violating the consensus reached with us and crossing the line to set up tents."

It said Chinese troops were able to drive their adversaries away in a "significant victory," and that the other side "ran away with their heads in their hands, abandoning numerous border-crossing and injured or dead personnel."

Beijing and New Delhi later sent tens of thousands of extra troops to the border.

The two sides said last week they had agreed to "disengage" along the border area.

Indian Defence Minister Rajnath Singh said the agreement would "substantially restore the situation to that existing prior to commencement of the stand-off last year".