Pimentel discussing proposed federal-presidential model pic.twitter.com/ARTcpypT89 — Christian Esguerra (@IanEsguerra) February 27, 2018

MANILA - Former Senate President Aquilino "Nene" Pimentel Jr. on Tuesday brought the "complicated" issue of Sabah ownership to the attention of the consultative committee, calling on the Philippine government to assert its claim over the disputed territory.

But Pimentel said the Philippines should "make sure not to unnecessarily antagonize our friend Malaysia," which has been administering Sabah for decades.

The Philippines should also "use only methods recognized by the United Nations for settling disputes between and among sovereign nations," he told the committee formed by President Rodrigo Duterte to draft a new federal constitution.

"Sabah is ours although this issue of the ownership of Sabah is rather complicated," he said while discussing his proposed federal-presidential form.

Responding to Pimentel’s proposal, Kuala Lumpur earlier made it clear it would not entertain any claim over Sabah, which joined the Federation of Malaysia in the 1960s.

The Sultan of Sulu received Sabah from the Sultan of Brunei for helping quash a rebellion in the 17th century.

The Philippines insists the disputed territory was merely leased in an 1878 deed between the Sultanate of Sulu and a British firm.

A supposed proof is the regular payment of around P70,000 by Malaysia to the heirs of the Sultan of Sulu to this day. Malaysia considers it "cession money."

"The sooner we assert our ownership over Sabah, the better it will be for our people and our country," Pimentel said.

Forces identified with the Sultan of Sulu, Jamalul Kiram, asserted the claim in 2013, launching an attack on Lahad Datu, Sabah.