Top Chinese and Indian generals are to meet in a Himalayan outpost on Saturday in a bid to end the latest frontier showdown between the world's two most populous nations that has seen thousands of troops sent to both sides.
Ahead of the talks, here are the key points that have led to the dispute and the pitfalls as the two nations, who fought a 1962 border war and have clashed many times since, over the solution:
Fist-fights and handshakes at the frontier
On May 9 several Indian and Chinese troops were injured in fights with fists, stones and wooden batons in Sikkim state.
Indian officials say that within days, Chinese troops had encroached on the Indian side of their demarcation line in the Ladakh region further to the west.
India has moved extra troops to positions opposite. The generals are to meet at a point near the face-off known as Chushul-Moldo for the highest-level talks since the fisticuffs, according to military sources.
A line out of control
Experts say that new roads on the Indian side of the line may have rankled China.
But the dividing line between India and China is more like a scar — that includes a ceasefire Line of Actual Control — than a border.
They cannot even agree how long it is. India gives a figure of 3,500 kilometres (2,175 miles). China does not give a number, but state media says the border should be just 2,000km (1,250 miles) when China's claims in Jammu, Kashmir, Ladakh and other regions are taken into account.
Each side uses different frontier proposals made by Britain to China in the 19th century to back their claims.
Increasingly tense border talks and a series of skirmishes led to the 1962 war, mainly fought above 4,000 metres (14,000 feet), in which China took territory from India in Arunachal Pradesh.
Regular clashes have followed and the rival sides staged a 73-day showdown in the Doklam Plateau in 2017.
India-China powerplay
High altitude face-offs have become more frequent in recent years. There have been four since President Xi Jinping took power in 2012.
The US administration has said this is a new sign of China's growing military assertiveness.
India has also taken a tougher line on security since nationalist prime minister Narendra Modi took office in 2014.
"India does not want to hurt any country's pride neither can it tolerate if a country wants to hurt ours," said Defence Minister Rajnath Singh last week.
Tamanna Salikuddin, a South Asia expert at the US Institute of Peace think tank, linked the tensions to India's fierce rivalry with Pakistan, an ally of China.
"From the Indian perspective, China’s aggression is seen as supportive of Pakistan’s efforts to contest the borders with India in this highly inflammable region."
No shots since 1975
While India and China are better armed and more stubborn, no shots have been fired across the disputed border since 1975. Diplomats say this is part of an unofficial 'de-escalation pact'.
And while they blame each other for the latest flare-up and both countries are looking for diversions from the global pandemic crisis, both insist negotiating avenues such as the Chusho-Moldo talks can act as a safety valve for their frustrations.
Salikuddin said there is a risk of escalation because of the high number of "troops and heavy weaponry" in the zone but the two sides have a "robust conflict management arrangement".
And ultimately there is growing recognition that India and China cannot live without each other.
India's Finance Minister Nirmala Sitharaman told WION TV this week that once the pandemic is over "if there are two engines of growth for the global economies… it is only two countries and they are India and China."