India and China said on Monday that they had made progress disengaging frontline troops from a months-long standoff along a disputed part of their border where a brawl in June left 20 Indian soldiers dead.

Special representatives on the border issue, India's national security advisor Ajit Doval and China's Foreign Minister Wang Yi, spoke by phone on Sunday about the issues along the frontier known as the Line of Actual Control (LAC), according to India's foreign ministry.

"The representatives agreed that maintenance of peace and tranquility in the India-China border areas was essential for the further development of our bilateral relations and to complete the ongoing disengagement process along the LAC expeditiously," the ministry said on Monday in a statement.

An Indian defence ministry official told The Associated Press that Chinese troops were observed removing tents and structures near the Galwan Valley along the disputed border.

He spoke on the condition of anonymity because he wasn't authorised to speak to reporters.

Asked about a Chinese withdrawal, China's Foreign Ministry spokesperson Zhao Lijian said only that the two sides made positive progress in disengaging frontline troops and easing the border situation with effective measures in a third round of military talks on June 30.

Both sides blamed each other for the June 15 clash in the remote river valley in the Karakoram mountains of Ladakh where India is building a strategic road connecting the region to an airstrip close to China.

Soldiers fought in hand-to-hand combat with fists and clubs, but not with firearms, deferring to an agreement not to use them. India said 20 of its soldiers were killed, as were Chinese soldiers. Chinese officials have not confirmed any casualties.

Chris Biggers, senior analyst at the geospatial intelligence company HawkEye 360, has said a review of satellite images showed China was moving construction equipment, soldiers and military hardware toward the LAC before and after the clash.

China and India fought a 1962 war over their disputed border, an area that covers nearly 3,500 kilometres. That fighting ended in an uneasy truce and the creation of the LAC, which stretches from Ladakh in the north to the Indian state of Sikkim in the northeast.

The two countries have been trying to settle their border dispute since the early 1990s, without success.

Indian Prime Minister Narendra Modi made an unannounced visit on Friday to a military base in Ladakh, telling troops that the days of expansionism are over.

“Expansionism creates danger for world peace. This is an era of development. Expansionist forces have either lost or forced to turn back," he said in an apparent reference to China.