CLARK, Philippines (AP) — The top U.S. diplomat in the Philippines said Tuesday the U.S. has no credible reports of human rights violations by the Philippine armed forces or police during their five-month campaign to oust Islamist militants from the southern city of Marawi.

"There were no credible reports or allegations that the armed forces of the Philippines engaged in any abuse or any activity that violated human rights of people of Marawi," Ambassador Sung Y. Kim, said in an interview with U.S. reporters, adding, "It's quite positive that the Philippines military behaved in a responsible manner in a very difficult situation."

Kim said the U.S. military provided surveillance aircraft and other equipment to help monitor and assess the militants' positions during the Marawi campaign. He said this assistance was critical to a successful outcome.

Kim said the extent of the militants' infiltration of Marawi was a surprise to both the U.S. and Philippine governments. They overran the city in May, setting off alarms in Southeast Asia and the West because of their affiliation with the Islamic State group.

The ambassador spoke on the sidelines of a meeting of defense ministers from the 10-nation Association of Southeast Asian Nations. The U.S. is not a member, but Defense Secretary Jim Mattis attended portions of the group's meetings and held separate talks with many of his counterparts.

US Ambassador to the Philippines Sung Kim says the US military aided Philippine troops, who recently defeated Islamic State-style militants in the city of Marawi. He said the US shared intelligence and provided technical advice and equipment. (Oct. 24)

Later Tuesday, Mattis was scheduled to meet with Philippines President Rodrigo Duterte, who earlier this week visited Marawi and announced its liberation from "the terrorist influence."

The U.S. has a treaty obligation to defend the Philippines from potential aggressors, but the relationship had deteriorated in recent years. Duterte last year called then-President Barack Obama a "son of a whore," and Obama canceled plans to meet with him.

President Donald Trump has praised Duterte for his violent crackdown on drug suspects. The two presidents are expected to meet when Trump travels to the Philippines next month as part of an Asia tour.

Kim, the U.S. ambassador, said Tuesday that relations have been improving this year.