New Delhi, April 15: The chief ministers of four northeastern states today put the onus of ending the decades-old boundary disputes within the region on Delhi and ?elder sister Assam?, the common factor in the long-drawn territorial disputes.

The chief ministers are in the capital to attend a conference on internal security. A gamut of issues, including insurgency, is expected to figure in the discussions.

?We have appealed to Assam and the Centre to find an amicable settlement to the border problem so that peace reigns,? Meghalaya chief minister D.D. Lapang told the media.

Nagaland chief minister Neiphiu Rio, who was also present at the news conference at Meghalaya House, criticised Assam?s approach to the problem. Assam prefers to wait for a Supreme Court judgement to resolve the issue, while Nagaland has made a case for an out-of-court settlement and a boundary commission to demarcate the territories.

Rio blamed Assam for allowing ?third parties? to settle in the border areas, which, he said, had strained relations between the two states.

?Illegal migrants have settled on a vast stretch of the border and Assam is the breeding ground of these migrants, who produce dubious documents to prove their citizenship. Why should people who don?t belong to the region be allowed to create trouble?? he asked.

Assam has boundary disputes with four states ? Nagaland, Arunachal Pradesh, Meghalaya and Mizoram. The recent incidents along the state?s border with Nagaland have sparked fears of a repeat of the Merapani clashes of 1986.

Almost all states in the region have apprised Delhi about the situation along the border. Union home minister Shivraj Patil recently assured the Nagaland chief minister that he would summon all concerned parties to Delhi for a discussion on the issue.

?Northeast issues should be regarded as national issues and more attention should be paid to them as in the case of Kashmir,? Mizoram chief minister Zoramthanga said, referring to the allocation of funds to the NEC over the past three years.

Lapang said that though there was no scope for the NEC to play a role in the security matters, it was becoming necessary now.

The chief ministers of the northeastern states were earlier against allowing the NEC to play a role in security.