"The Philippine military has already pre-empted the Maute group from establishing a wilayat or province in Marawi so the role of United States ... is to provide technical assistance as prescribed by the Constitution and we will abide by that".
Malacañang sought to allay fears that Marawi City was becoming a new hub for Islamist fighters in Southeast Asia.
Fighting in Marawi City has entered a fifth week, and almost 350 people have been killed, according to an official count.
JTF Marawi spokesperson Lt. Col. Jo-Ar Herrera (left) told reporters in a press conference at the Provincial Capitol in Marawi on Monday that government troopers are not using poison bomb during the ongoing military offensives against the members of Maute.
"We are closely watching certain groups and we hope they will not join the fight", Padilla said. "We need to address the situation".
It may be recalled that numerous sachets of shabu were recovered by troops in the fighting positions of the Maute and Abu Sayyaf terror group since the first and second week of the Marawi siege.
Abella said the Chief Executive had already accepted that the USA forces have to help the Philippine military in fighting the Maute group and purported Isis members, even after the latter earlier announced that he forbids the presence of foreign troops in the country.More news: United States responds to Russian threat after shoot-down of Syrian jet
But he also clarified that United States forces are not involved in actual ground offensives inside Marawi.
Amid the continuing military offensives against Maute bandits, the USA reportedly sent troops to assist Filipino soldiers in quelling the rebellion in Mindanao.
But Abella said the USA should only provide "technical assistance", noting that the law prohibits foreign troops from participating directly in combat operations.
He added that US' technical assistance would remain, as imposed by the Constitution.
After the military confirmed the American help, Duterte said he was "not aware of that". "So the role of the USA in relation to IS is to provide technical assistance, as prescribed by the Constitution and we will abide by that".
As of this posting, government forces killed in the four weeks of fighting is now at 58 with 206 Maute Group neutralized and 26 civilians executed since the conflict started last May 23.