In a statement on Wednesday, President Rodrigo Duterte said that he was pulling out of the Rome Statute for the "baseless, unprecedented and outrageous attacks" made by ICC chief prosecutor Fatou Besouda against him.
Presidential spokesman Harry Roque confirmed in a text message to reporters that the Philippines was withdrawing, as stated in a 15-page statement dated March 13 seen by reporters, which said the withdrawal was "effective immediately".
"The government affirms its commitment to fight against impunity for atrocity crimes, notwithstanding its withdrawal from the Rome Statute, especially since the Philippines has a national legislation punishing atrocity crimes", the note said.
The statute says withdrawal from the agreement takes effect a year after the United Nations secretary general receives a written request to leave.
The London-based rights group Amnesty International called the withdrawal "misguided" and "cowardly".
Roque, who was a prominent advocate for the Philippines' joining the ICC in 2011, said he was saddened by the President's decision but he supports Duterte's move.
Worldwide organizations and actors have become increasingly concerned over alleged human rights abuses under Duterte, as security forces continue to wage war on other destabilizing groups such as communists insurgents and the Islamic State.
According to the president, due to the fact that the Rome Statute was allegedly never published in the Official Gazette, the state's publication, it was therefore never in effect.
Centerlaw pointed out that the Philippine delegation brought with them to the Rome Conferences in 1998 "our rich jurisprudential heritage in worldwide criminal law, borne of our country's tragic experience in World War II, and embodied in the landmark war crimes cases of top generals of the Japanese Imperial Army - Tomoyuki Yamashita and Shegonori Kuroda".
Police deny allegations of murder and cover-ups and say they killed about 4,100 drug dealers in shootouts, but have nothing to do with an estimated 2,300 largely unsolved drug-related homicides.
According to worldwide law, Duterte and the Philippines are under the jurisdiction of the ICC as a result of being a member of the court, and withdrawing would not change that jurisdiction retroactively.
In recent months, the Philippine government has lashed out against United Nations rapporteurs on human rights, issuing threats against officials such as Agnes Callamard, who is investigating extra-judicial killings in the Philippines. He said the withdrawal was not a way to evade an ICC investigation. "Shit. Maniwala ka diyan", Duterte said.
Critics expressed shock at Duterte's decision, saying he was trying to escape accountability and fearing it could foster an even worse human rights situation in the country. The Duterte administration's obstinacy and truculence could result in a failure in the war on drugs despite more lives lost and eventually, the President and his top officials would be held accountable for their crimes against humanity and the Filipino people.
The shadow of potential ICC prosecution and the country's controversial withdrawal from the body will further complicate Manila's relations with Western partners, including Washington and Canberra, which have sought to maintain stable relations with the Southeast Asian partner. China has called on the worldwide community to respect the Philippines' sovereignty on the issue.