Australian war ships will make port visits to an enlarged naval base on Papua New Guinea, expanding the Navy’s presence to Australia’s north as concerns rise over Chinese interest in the region.

Prime Minister Scott Morrison revealed on Thursday afternoon he had signed an agreement with PNG counterpart Peter O’Neill for a joint redevelopment of the naval base at Lombrum, Manus Island.

Australia is expected to pay for much of the upgrade — a signal of the government’s eagerness to hold onto its status as PNG’s preferred security partner rather than risk having Beijing step in and fill the role.

“This initiative will further enhance interoperability between our defence forces, and deepen our maritime security co-operation, including through increased Australian ship visits over time,” Mr Morrison said.

He said the redevelopment of the base - which was established by the US during World War II and later used by Australian naval ships for resupply in the 1950s and 1960s - would more broadly boost the “strong partnership with the PNG national government” and provide economic opportunities for Manus Islanders.