President Rodrigo Duterte warned on Sunday that he would ask all the American forces in the country to leave, with the possibility of junking the Enhanced Defense Cooperation Agreement (EDCA) with the United States.

In a speech in Bacolod City during the opening of the Masskara Festival, the Chief Executive said that based on the EDCA official document, it was signed former Defense Secretary Voltaire Gazmin and an "aide." On behalf of the US government, its ambassador, Philip Goldberg, signed the document on April 28, 2014 in Manila.

"It does not bear the signature of the president of the Republic of the Philippines...there's no signature of Aquino," Duterte said.

"Better think twice now because I would be asking you to leave the Philippines altogether," Duterte added.

The President earlier said that the joint military exercises between the Armed Forces of the Philippines and the US Marines on October 4 to 12 would be the last war games by the Americans in the country under his administration.

Duterte has become critical of the US after President Barack Obama and the State Department criticized him for the alleged extrajudicial killings in the Philippines amid his war against illegal drugs.

"Those Americans, what I don't like is reprimanding me in public. That's why I said f...k you," he said, adding that instead of helping his administration how to address the drug menace, he was being castigated.

Duterte said he did not care even if the American businesses leave the country.

"We will not get hungry. We will get out," he said.

The President has said that the Philippines would further open up alliances with China and Russia.

Duterte also said almost all the insurgent groups in the country have already agreed to talk peace with his administration, except the terrorist Abu Sayyaf Group and a group of Muslim scholars because of the continued presence of the American soldiers in the country.

He said these groups, particularly the group of scholars, told him that as long as the Americans are in Mindanao, they would not negotiate for peace.

"That prompted me to say there will be a time that I may ask the Americans to leave Mindanao to enable me to connect to them and to talk. May be they will decide to negotiate," he added.

During his attendance to a regional summit in Laos last month, Duterte, who was a mayor of Davao City for 23 years, veered away from his prepared intervention and presented to his counterparts, including Obama, pictures of Moros who were massacred in Mindanao about a century ago.

He said when he told the Muslim scholars that the incident took about 100 years ago, their response to him, "no, mayor, that picture is present tense."

Duterte said he would soon meet with Moro National Liberation Front founding chairman Nur Misuari in Davao City as he would give him a safe conduct pass.

Misuari, a fugitive, allegedly masterminded the Zamboanga siege in 2013. Celerina D. Monte/DMS