India and China have reached a deal on patrolling their disputed frontier to end a four-year military stand-off, the Indian foreign minister said on Monday, paving the way for improved political and business ties between the Asian giants.

The news came on the eve of Indian Prime Minister Narendra Modi's visit to Russia for an Oct. 22-24 summit of the BRICS regional grouping, during which he could hold talks with Chinese President Xi Jinping, Indian officials said.

Relations between the world's two most populous nations - both nuclear powers - have been strained since clashes between their troops on the largely un-demarcated frontier in the western Himalayas left 20 Indian and four Chinese soldiers dead in 2020, Reuters reported.

The two sides had since stopped patrolling several points along the border in the Ladakh region to avoid new confrontations, while moving tens of thousands of new troops and military equipment closer to the freezing highlands.

"We reached an agreement on patrolling, and with that we have gone back to where the situation was in 2020 and we can say ... the disengagement process with China has been completed," Indian Foreign Minister Subrahmanyam Jaishankar said at a NDTV media conclave.

The "understanding was reached only today," he said, adding: "We always said that if you disturb the peace and tranquility how can the rest of the relationship go forward?"

To avoid clashes, the two militaries will patrol contested points along the border according to an agreed schedule, a senior Indian military officer aware of the details told Reuters.

Both sides will monitor the area in Ladakh to ensure that there are no violations, the officer added.

Authorities in Beijing offered no immediate response to India's remarks.

Officials in New Delhi said the pact clears the path for a likely bilateral meeting between Modi and Xi on the sidelines of the BRICS summit, which will be their first since 2020.