Eritrea on Friday withdrew from the Intergovernmental Authority on Development, accusing the East African regional bloc of nations of acting against the country’s interests.

At the same time, the United Nations expressed concern over renewed tensions between Eritrea and neighboring Ethiopia, which signed a peace agreement 25 years ago.

Eritrea’s foreign ministry said in a statement Friday it was withdrawing “from an organization that has forfeited its legal mandate and authority; offering no discernible strategic benefit to all its constituencies and failing to contribute substantively to the stability of the region.”

Eritrea quit IGAD in 2003 and rejoined two years ago, but said Friday that the bloc had failed to contribute to regional stability. IGAD responded by saying Eritrea had not participated in regional activities since it rejoined.

In addition to Eritrea and Ethiopia, IGAD includes Djibouti, Kenya, Somalia, South Sudan, Sudan and Uganda. The organization works on regional policies concerning trade, customs, transport, communications, agriculture, natural resources and the environment, according to its website.

Eritrea and Ethiopia have in recent months accused each other of interference, sparking concerns over the possibility of a return to hostilities.

Ethiopia said it wants to peacefully gain Red Sea access through Eritrea, which it relied on heavily for trade before the secession. Ethiopian Prime Minister Abiy Ahmed said in September it was a “mistake” to lose access to the sea when Eritrea gained independence in 1993 by seceding from Ethiopia to form a separate nation. Abiy’s rhetoric has been seen as provocative by Eritrea.

The office of U.N. Secretary-General Antonio Guterres on Friday urged the two countries to “recommit to the vision of lasting peace and the respect for sovereignty and territorial integrity.”

The U.N. cited the Algiers Agreement signed in 2000, which ended nearly three decades of border war between Eritrea and Ethiopia. The U.N. called for a recommitment to the agreement, which it described as a “crucial framework” for peace.

Eritrea accused Ethiopia in June of having a “long-brewing war agenda” aimed at seizing its Red Sea ports. Ethiopia recently claimed Eritrea was “actively preparing to wage war against it,” as well as supporting Ethiopian rebel groups.