The Solomon Islands and Vanuatu have signed a border agreement to further strengthen the "cultural and historical ties" between the two Melanesian nations.
The Tirvau Agreement was signed by the prime ministers of the two countries in Honiara on 21 June.
The agreement is expected to boost cross-border relations between Solomon Islands' Temotu and Vanuatu's Torba provinces.
Temotu is the easternmost province of Solomon Islands, located closer to Vanuatu than Honiara, while Torba - comprised of Torres and Banks island groups - is the northernmost and least populous province of Vanuatu.
The Solomon Islands Ministry of Foreign Affairs and External Trade (MFAET) said in a press release Tirvau is the feather money used by the people of Temotu.
"It signifies the diversity that exists in our countries and the value placed on our relations.
"The Tirvau basic border Agreement is the overarching framework that will govern and regulate the joint border arrangements and movements between the maritime border of Solomon Islands and Vanuatu."
The agreement is an extension of the Motalava Treaty between the two nations signed in October 2016, MFAET said.
Vanuatu Prime Minister Charlot Salwai said the areement is a testament that "we are one people, custodians of one solwara and that Melanesia is a reality".
"Tirvau has been a powerful trading system for our ancestors over thousands of years between the people from Temotu Province in the Solomon Islands and people from Torba Province in Vanuatu.
"Tirvau connects our two people and Tirvau brought peace and harmony between our two people.
"It is my hope and believe that the Agreement we sign today will continue to strengthen and bridge between our two people and to bring peace and harmony to our people."
His counterpart, Jeremiah Manele, said the agreement is about promoting peaceful relations, facilitating economic activities, and ensuring the effective governance of borders and cooperation on sectoral and humanitarian issues of mutual concern.
The agreement cements and binds current relations with a umi tugeda spirit, two wantok countries further formalising and recognising the traditional and cultural connections as Melanesians, Manele said, according to the MFAET release.
The border agreement will also allow for more visibility and transaction between the two countries for stronger connectivity, trading and economic growth.
While the two governments did not provide a date on when the framework comes into effect, Manele called on implementing authorities to be diligent in activating and operationalising the border agreement.
Meanwhile, Salwai said "embedded in the Tirvau Agreement is the spirit of the Melanesian way" and the signing of the agreement with Solomon Islands could set the platform for future border arrangement framework with other Melanesian countries.
"Vanuatu will seek to establish similar border arrangements with the government of New Caledonia (Kanaks) and the government of Fiji.
"We Melanesians must maintain our relationships in the Melanesian way."