As the number of on-the-spot killings of drug offenders skyrockets in the Philippines, the United States is urging President Rodrigo Duterte's government to ensure that law-enforcement efforts "comply with its human rights obligation".
The US State Department comment on Monday followed the release of Philippines police figures showing there have been about 1800 drug-related killings since Duterte took office seven weeks ago and launched a war on narcotics.
The number is far higher than previously believed.
"We are concerned by reports regarding extrajudicial killings of individuals suspected to have been involved in drug crimes in the Philippines," State Department spokeswoman Anna Richey-Allen said.
"The United States believes in the rule of law, due process, and respect for universal human rights, and that these principles promote long-term security."
A day after President Rodrigo Duterte lashed out over United Nations criticism of the wave of deaths in the Philippines, newly-revealed figures show the number of drug-related killings since Duterte took power and declared war on drugs May has doubled to about 1800.
Duterte said, in a bizarre and strongly worded late-night news conference on Sunday, the Philippines might leave the UN and invite China and others to form a new global forum.
However, Duterte's foreign minister, Perfecto Yasay, said on Monday the Philippines would remain a UN member and described the president's comments as expressions of "profound disappointment and frustration".
"We are committed to the UN despite our numerous frustrations and disappointments with the international agency," Yasay told a news conference.
Last week, two UN human rights experts urged Manila to stop the extra-judicial executions and killings that have escalated since Duterte won the presidency in May on a promise to wipe out drugs.
As recently as Sunday, the number of suspected drug traffickers killed in Duterte's seven-week war on drugs had been put at about 900 by Philippine officials.
However on Monday, Philippine National Police Chief Ronald Dela Rosa told a Senate committee investigating extra-judicial killings that 712 drug traffickers and users had been killed during police operations. Police were also investigating 1,067 drug-related killings outside normal police work, Dela Rosa said.
The latest figures had been compiled since July 1, he said.