MANILA (Philippine Daily Inquirer/Asia News Network) - President Rodrigo Duterte has acknowledged military assistance from the United States and China, and said he would welcome any aid from Russia in the fight against ISIS-inspired militants in Mindanao where he had declared martial law.

Militants who have pledged allegiance to the Islamic State in Iraq and Syria are among the hundreds of militants who have been occupying parts of the Mindanao city of Marawi for almost two months despite a massive military operation to crush them.

Addressing diplomats in Davao City on Friday, the President said the Philippines would "stay with the Americans" under a 66-year-old defence treaty, but he again reminded Washington not to meddle with the way he runs the country, especially his human rights record and his bloody war on drugs.

"Let us give credit where credit is due. The United States helped the Armed Forces in this fight, and China committed and delivered a lot of firearms for us," Mr Duterte said in a speech to delegates attending the 11th Ambassadors' Tour.

"I don't know about Russia but [Russian President Vladimir] Putin, he said he will help. I welcome all of that," he added.

He told diplomats there were no strings attached to the 370 million pesos (S$10.02 million)worth of arms and ammunition from China that he had personally received on June 28 during turnover ceremonies at Clark Air Base in Pampanga province.

"You have to make friends, and there is a need for you to acquire the kind of firearms and they are there. There are no attachments there," he said.

He said no head of state would say, "'Oh, I'll give you but you should be loyal.'"

"There's nothing like that," he said, adding that leaders would just say, "'Yes, we can help you.' That is all."

The US Embassy had earlier donated counterterrorism weapons and equipment to the Philippines. These included 300 M4 carbines, 200 Glock 21 pistols, four M134D Gatling-style machine guns and 100 M203 grenade launchers.

Philippine defense officials said US Special Forces also were helping government troops fighting ISIS-linked gunmen in Marawi City by flying surveillance planes and drones. The Americans were not involved in ground combat, which is prohibited by the Constitution, they said.

The government has also accepted similar assistance from the Australian government.

Mr Duterte said the 1951 Philippines-US Mutual Defense Treaty was "still there, so I cannot enter into military alliances with other nations because I would be violating the US-RP agreement."

"We stay here with the Americans," he added.

However, the President said he had "misgivings" about the alliance, especially with Americans lecturing him on human rights.

"Nobody should teach me how I should do it. America started with these human rights commissions. They were talking before the public through media … with the admonition and criticising me," he said.

"So, I just let it pass. It's the media. But then, the US Department of State and then the spokesperson of their presidential office criticised me and castigated me. I fought back," he said.

He said former US President Barack Obama then talked publicly about him and his leadership.

"So I told him-and these [ARE]my exact words … 'Son of a bitch. Do not tell me what to do,'" Mr Duterte said. "I am not a Federal Postal employee. I said, 'You can go to hell, Mr. Obama."

"Why would you scold me? I am a head of state, you are a head of state. You are a President, I am a President. You have your own race, your tribe to protect, I have mine," he added.