On Thursday, the governments of Assam and Arunachal Pradesh signed a memorandum of understanding (MoU) in the presence of Union Home Minister Amit Shah in New Delhi over disputed areas along their shared border of about 800 km, which Shah called “historic”, Indian Express reported.

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

Assam and Arunachal Pradesh share a border of 804.1 km long. The two states have been discussing resolving the dispute, and last July, Sarma and Khandu signed the Namsai Declaration, promising to find a solution as soon as possible.

The two northeastern states have decided to settle the dispute over 123 villages spanning 12 districts in Arunachal Pradesh and eight in Assam.

Under the MoU, the state government has agreed that no new claim areas or villages will be added beyond these 123 villages. It also noted that the two governments “agreed to prevent any new encroachment in the border area effectively”. It agreed that the MoU on the 123 villages is “full and final”.

Of the 71 villages reached under the understanding, 1 village in Arunachal Pradesh will be incorporated into Assam, 10 villages will remain in Assam, and 60 villages in Assam will be incorporated into Arunachal Pradesh.

“Of the remaining 52 villages, the boundaries of 49 villages will be finalised by regional committees in the next six months, while the three villages within the IAF bombing range will require rehabilitation,” the Assam government said.

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

Arunachal CM also described the deal as “historic”. “This is an issue that has been happening for about 50 years. I must thank Assam CM Himanta-Dada, it is because of his political will that this has happened. With this resolution involving 123 villages, Assam and peaceful coexistence between Assam and Arunachal Pradesh will only increase,” he said.

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

Arunachal Pradesh has been arguing that several forest patches on the plains traditionally belonged to hill tribe chiefs and communities and were earlier “unilaterally” transferred to Assam. After Arunachal Pradesh statehood in 1987, a tripartite committee was appointed to recommend the transfer of certain territories from Assam to Arunachal Pradesh.

However, Assam opposed this, and the matter reached the doors of the Supreme Court.