Malaysia’s state oil company Petronas signed an agreement with Brunei on April 5 to jointly develop two offshore oil fields.

The Gumusut-Kakap and Geronggong-Jagus East fields straddle the two countries’ maritime boundary. The tiny sultanate of Brunei is surrounded by the Malaysian state of Sarawak on the north coast of the island of Borneo.

“Having now formalized this landmark agreement, Petronas believes that both parties can look forward to continuing the strong momentum towards developing our nations’ energy sectors for the long-term growth and prosperity of both Brunei and Malaysia,” Petronas group CEO Tengku Muhammad Taufik said in a statement.

Malaysian Prime Minister Muhyiddin Yassin and Brunei Sultan Hassanal Bolkiah issued a separate joint statement, expressing hopes for more cooperation, including for the development of gas resources.