MANILA - President Rodrigo Duterte is "a man who must be stopped," US based-publication The New York Times said Wednesday as it urged the International Criminal Court (ICC) to look into the alleged mass killings linked to the firebrand leader.

Lawyer Jude Sabio on Monday filed a complaint before the ICC, alleging that Duterte ordered the killings of thousands of people through a death squad when he was still mayor of Davao City and until now that he waged a brutal crackdown on narcotics.

In a scathing editorial titled "Let The World Condemn Duterte," New York Times said the ICC should "promptly open a preliminary investigation" into the allegations.

The publication said although the ICC may be reluctant to start the investigation because of its role as a court of last resort and Duterte's popularity among Filipinos, there was "more than enough evidence" against the President.

New York Times noted that 2 self-tagged hitmen have confessed that Duterte paid members of a death squad to hunt down suspected criminals and his political opponents when he was still mayor of Davao City.

After he was elected president last May, Duterte "took the killing campaign nationwide, effectively declaring an open season for police and vigilantes on drug dealers and users," the editorial said.

It added that rights groups Amnesty International and Human Rights Watch, as well as several Filipino politicians have also accused Duterte of mass killings.

If these were not enough evidence, New York Times said the ICC may take into account the "savage words" of Duterte when he said he would be "happy to slaughter" 3 million drug addicts.

A preliminary investigation against Duterte, the publication said, will encourage the international community to take measures against him, such as imposing tariffs on Philippine goods.

This was not the first time that New York Times called for accountability for Duterte. In an editorial last March, it urged the international community to revoke Manila's trading privileges over the killings linked to the President's war on drugs.

• NY Times wants accountability for Duterte: 'Hit PH where it hurts most'

Duterte has persistently denied involvement with any death squad and said that his orders to kill drug suspects come with the caveat that police should operate within the bounds of the law.

Malacañang earlier said New York Times was part of a "demolition job" against the Duterte administration.

Ernesto Abella, a spokesman for Duterte, dismissed the ICC complaint as a "cynical effort" to undermine the president.

"The so-called extra-judicial killings are not state-sanctioned or state-sponsored," Abella said in March. "The intent of this filing in ICC is clearly to embarrass and shame the president, and undermine the duly constituted government of the Philippines."

Since it was set up in July 2002, the ICC has received over 12,0000 complaints or communications. Nine of these cases have gone to trial and six verdicts have been delivered.

The ICC has no powers of enforcement, and any non-compliance has to be referred to the United Nations or the court's own oversight and legislative body, the Assembly of States Parties.

The complaint is only a possible first step in what could be a long process at the ICC. The tribunal first has to decide whether it has jurisdiction, and then decide whether it should conduct a preliminary examination.

It can then ask a judge to open an official investigation, which could lead to a trial. -- With a report from Reuters