Four years ago, several soldiers from both sides were killed in a bloody melee. Any thaw between the countries could have global implications.

India and China have reached an agreement on military disengagement along their disputed border, New Delhi said, a step toward reducing frictions between the nuclear-armed neighbors that comes as both countries’ leaders arrive in Russia for a summit.

China and India reached a deal over their disputed Himalayan border to help defuse a four-year military standoff marked by violent skirmishes. The pact between the world’s two most populous countries — in which both sides agreed to alternately patrol contested areas to ensure no border violations — came just ahead of the BRICS summit in Russia.