The Assam and the Arunachal Pradesh governments signed a Memorandum of Understanding (MoU) in presence of Union Home Minister Amit Shah in New Delhi over disputed areas along the roughly 800-km shared boundary on Thursday, which Shah termed as “historic”, reported The Indian Express.

Assam Chief Minister Himanta Biswa Sarma and his Arunachal Pradesh counterpart Pema Khandu signed the agreement.

Assam and Arunachal Pradesh share an 804.1-km-long border. The two states had been in discussions to resolve the dispute, with Sarma and Khandu signing the Namsai Declaration in July last year, pledging to find a solution soon.

The two north-eastern states had decided to resolve the dispute in 123 villages that stretch across 12 districts of Arunachal Pradesh and eight of Assam.

According to the MoU, the state governments have agreed that no new claim area or village will be added in future beyond these 123 villages. It also states that both governments “agree to effectively prevent any new encroachment in the border areas”, and agree that the MoU is “full and final” with respect to the 123 villages.

Of 71 villages over which an understanding has been reached, one village from Arunachal Pradesh will be included in Assam, 10 villages will continue to be in Assam, and 60 villages from Assam will be included in Arunachal Pradesh.

“Of the remaining 52 villages, the village boundary of 49 is to be finalised by the regional committees in next six months, while three villages inside the IAF bombing range will require rehabilitation,” the Assam government said in a statement.

Assam CM Sarma later told news agency PTI, “The 50-year-old border dispute (between Assam and Arunachal) has been resolved today under Amit Shah’s guidance, with the blessings of Prime Minister Modi and due to a matured approach taken by governments of both states.”

The Arunachal CM also described the deal as “historic”. “It’s an issue that has been going on for around 50 years…. I must thank Assam CM Himanta-Dada, it is because of his political will that this has happened.… With this resolution of 123 villages, the peaceful coexistence between Assam and Arunachal will only increase,” he said.

Last year, regional committees were formed, comprising ministers, local MLAs, and officials from both sides, to facilitate discussions.

Arunachal Pradesh had been arguing that several forested tracts in the plains traditionally belonged to hill tribal chiefs and communities and were “unilaterally” transferred to Assam earlier. After Arunachal Pradesh achieved statehood in 1987, a tripartite committee was appointed, which recommended certain territories be transferred from Assam to Arunachal Pradesh.

However, Assam had contested it, and the case reached the doors of the Supreme Court.