Assam and Arunachal Pradesh share an 804.1-km-long border.
The Assam and the Arunachal Pradesh governments on Thursday signed an agreement in presence of Union Home Minister Amit Shah here to resolve their decades old border disputes.
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 have been in discussions to resolve the border dispute with Mr Sarma and Mr Khandu signing the Namsai Declaration on July 15 last year wherein they had pledged to find a solution soon.
Officials said the two states decided to resolve the dispute in 123 villages.
Mr Shah termed the border agreement as a "historic" event and said it ended decades long disputes.
Mr Sarma said the deal is a "big and successful" moment.
Mr Khandu described the deal as "historic". Regional committees dealing with specific areas were formed last year, comprising ministers, local MLAs, and officials from both sides to take the discussion forward.
Arunachal Pradesh, which was made a union territory in 1972, has been maintaining that several forested tracts in the plains traditionally belonged to hill tribal chiefs and communities and these were "unilaterally" transferred to Assam earlier.
After Arunachal Pradesh achieved statehood in 1987, a tripartite committee was appointed, which recommended that certain territories be transferred from Assam to Arunachal Pradesh.
Assam contested this and the matter was in the Supreme Court for a long time.
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