Build up at the Line of Actual Control on the disputed border between China and India is seen in this handout satellite image of Pangong Lake courtesy of Planet Labs taken May 27, 2020

NEW DELHI/SRINAGAR: US Secretary of State Mike Pompeo and a senior congressional leader have reprimanded China for bullying behaviour towards India during a military standoff on their disputed border.

Thousands of Indian and Chinese troops have faced each other for weeks at three or four locations in the western Himalayas after Beijing's forces intruded into Indian territory, according to Indian security officials and local media.

China denies it breached the "Line of Actual Control", as the 3,488 km de facto border is known, and says there is stability in the area near the Galwan River and Pangong Tso lake in the remote snow deserts of India's Ladakh region.

In comments released by the State Department, Pompeo told the American Enterprise Institute think-tank that China's moving of troops to the line of control echoed similarly heavy-handed behaviour over the Coronavirus, South China Sea and Hong Kong.

"These are the kinds of actions that authoritarian regimes take," he said.

One possible trigger for frictions is India's construction of a road near the Galwan valley to narrow the gap with China's superior network of roads that it built years ago, Indian and foreign military experts say. China is opposed to any Indian construction in the area, saying it is disputed territory.

The chairman of the US House Committee on Foreign Affairs, Eliot Engel, said China should respect norms and use diplomacy to settle the border issue with India.

"I am extremely concerned by the ongoing Chinese aggression along the Line of Actual Control," he said.

"China is demonstrating once again that it is willing to bully its neighbours rather than resolve conflicts according to international law," he added in a statement on Monday.

Soldiers are billeted in tents and both sides have brought in artillery and other heavy equipment to back them up, Indian officials said. India has also started construction of an emergency landing strip near the main highway of Kashmir which adjoins Ladakh.

Konchok Stanzin, a resident of Lukung village on the Indian side, about 40 kilometres from the border, said thousands of Indian troops had arrived in the last week alone.

"There is panic in the village as the area has never seen such a military buildup," he said.