Most previous stand-offs were resolved with both sides withdrawing their forces.
Highlights
- China wants border row resolved before BRICS summit next month: Diplomats
- On Wednesday, China ramped up its rhetoric over the stand-off
- Talks happening behind the scenes, but with little apparent progress
China is taking an increasingly tough line on a border row with India and President Xi Jinping looks set for an awkward encounter with Prime Minister Narendra Modi at the multilateral BRICS summit next month.
Diplomats say Beijing would like to resolve the border issue before a summit of the BRICS nations - that also groups Brazil, Russia and South Africa - in the Chinese city of Xiamen in early September, and ensure nothing dampens what China wants to be a show of cooperation and friendship among developing countries.
But that could be tough. On Wednesday, China ramped up its rhetoric over the stand-off, accusing India of "concocting" excuses.
"China will take all necessary measures to safeguard its legitimate and lawful rights and interests," the Foreign Ministry said.
The dispute at the Sikkim border began in June after the Chinese army tried to build a road near the tri-junction of Bhutan, China and India. China claims that in June, Indian troops crossed the border at Sikkim and stopped the Chinese army from constructing a road.
Responding, India reiterated an earlier line that work by a Chinese road crew in the sensitive frontier area would have changed the status quo and urging "utmost restraint" by all sides.
"India considers that peace and tranquility in the India-China border areas is an important pre-requisite for smooth development of our bilateral relations with China," Ministry of External Affairs said in a statement on Wednesday evening.
Most previous standoffs, such as one in 2014 just ahead of a rare trip to India for Xi, were resolved with both sides withdrawing their forces.
Talks are happening behind the scenes, but with little apparent progress. Meantime, Chinese and India media have been taking a strident approach, with a Chinese state-run newspaper last week saying China could use force.
The Indian government has asked political parties to refrain from politicising the issue and allow diplomacy to work.
China's defence ministry last week also warned India not to harbour any illusions about the Chinese military's ability to defend its territory.
A source with ties to the military, who spoke recently to a senior Chinese officer involved in the stand-off, said China has no appetite for conflict with India but could not be seen to be weak.
"Nobody wants to fight about this, but if India keeps making trouble then we'll have to show them what we're made of," the source said, citing the conversation with the senior officer.
China has repeatedly called on India to withdraw its forces.
An Indian government source closely tracking the standoff said there was no change in the ground situation in Doklam, with the two sides remaining in a stand-off.
© Thomson Reuters 2017