The Philippines would not allow the United States to participate in the combat operations, including the reported planned airstrikes against the Islamic State-linked terrorist groups in Marawi City, Malacanang said on Tuesday.

In a statement, Presidential Spokesperson Ernesto Abella noted that the fight against terrorism is not a sole concern of the Philippines but must be shared by the community of nations.

While the Philippines and the US have 'solid and robust" military alliance, however, he stressed the US aid to the Armed Forces of the Philippines is limited to technical assistance and information sharing and training.

"We have standing protocols which are in place under the Mutual Defense Board-Security Engagement Board with the US under the purview of the PH-US Mutual Defense Treaty of 1951. It does not involve any boots on the ground nor any direct participation in combat operations, such as the airstrikes reportedly being planned against Daesh-inspired groups in the Philippines," he said.

"This is a matter prohibited by our law and Constitution," Abella added.

He said there was no discussion of air strikes when Duterte visited the Joint Special Operations Task Force Trident in Marawi.

NBC News reported, quoting two US defense officials, that Pentagon is considering a plan allowing US military to conduct airstrikes on the ISIS in the Philippines.

The Filipino forces have been pursuing ISIS-inspired Maute Terror Group, which attacked and started occupying Marawi City on May 23, prompting Duterte to declare martial law in the whole of Mindanao.

In an interview with reporters on Monday night shortly after meeting US State Secretary Rex Tillerson in Malacanang, Duterte refused to divulge what he discussed with the foreign

diplomat, saying it was "confidential." Celerina Monte/DMS