The leaders of the Philippines and Indonesia met in Manila on Wednesday to discuss developments in the South China Sea and efforts to build closer ties among Southeast Asian nations, among a range of issues.

The meeting comes after Indonesian Foreign Minister Retno Marsudi said on Tuesday her country was ready to work with other Southeast Asian nations to finalise a long-delayed code of conduct for the South China Sea.

China lays claim to almost the entire waterway, a conduit for more than $3 trillion in annual maritime commerce, but its claims overlap those of Brunei, Indonesia, Malaysia, the Philippines and Vietnam, all members of the ASEAN grouping.

"President Widodo and I had a fruitful and honest discussion on regional events of mutual interest," Philippine President Ferdinand Marcos Jr, who hosted his Indonesian counterpart Joko Widodo, told a joint press conference after the meeting.

These included issues regarding the South China Sea, as well as ways to build co-operation among members of the Association of Southeast Asian Nations (ASEAN), he added, without giving details.

The neighbours also signed a pact on energy ties to aid co-operation between their business sectors during periods of critical supply constraints on fuels such as coal and liquefied natural gas.

In addition, they agreed to beef up defence ties and existing pacts on border co-operation, Widodo told the conference.

"We agreed to ... expedite revision of joint border patrol and crossing agreements, (and) also to strengthen defence co-operation, including on military hardware," he added.

A 2014 pact between the archipelago nations demarcated their maritime borders in the overlapping exclusive economic zones of the Mindanao and Celebes Seas, while a 1975 border patrol agreement aims to combat crimes at sea from piracy to smuggling.

For years, ASEAN and China have been trying to set up a framework to negotiate the code of conduct, a plan dating from 2002. But progress has been slow despite commitments by all parties to advance and expedite the process.

In 2016, the Permanent Court of Arbitration in the Hague said China's claims had no legal basis. China has rejected that ruling.

Tension has flared in recent months between China and the Philippines as they have traded accusations over several run-ins in the waterway. (Reporting by Neil Jerome Morales in Manila and Ananda Teresia in Jakarta; Editing by Kanupriya Kapoor and Clarence Fernandez)