Doklam is a disputed area close to the tri-junction between India, China and Bhutan. China and Bhutan have engaged in a long territorial dispute over the area.
China has cited an 1890 Britain-China treaty to back its claim on Doklam. The treaty, called the Convention between Great Britain and China relating to Sikkim and Tibet, has been repeatedly cited by China in reference to the ongoing military standoff. It was signed by British viceroy Lord Lansdowne and lieutenant governor Sheng Tai in 1890.
On Thursday, Chinese foreign ministry spokesman Lu Kang had displayed two photographs of the alleged Indian "incursion" into the area. On the same day, the Bhutanese border was put on high alert and border security was tightened as a result of the growing tensions.
One of the photos showed two bulldozers which China claimed to belong to the Indian military. A redline in the photos was showed as "Chinese side of the border".
A standoff followed between the Indian and Chinese military after India blocked the construction of the road by China in Doklam. Over 3,000 troops have been deployed by the two nations along the border area as a precautionary step.
Beijing has now demanded withdrawal of Indian troops from the Sikkim sector as a precondition for "meaningful dialogue" to resolve the situation.
(With inputs from PTI)