The United Nations' special rapporteur on extrajudicial killings condemned Friday the use of violence to combat illegal drugs, as she made a surprise visit to the Philippines that angered President Rodrigo Duterte.
Agnes Callamard had since last year wanted to travel to the Philippines to investigate Duterte's drug war, which has claimed thousands of lives and led to warnings he may be orchestrating a crime against humanity.
In a speech at a state-run Manila university, Callamard warned of the many pitfalls of governments globally adopting violent responses to illegal drugs, and said she had been watching events in the Philippines closely.
"The 'war on drugs' does not work," Callamard said.
She praised people in the Philippines who had spoken out against Duterte's drug war.
"I have followed testimonies of the relatives of victims, I have seen the brave work of civil society actors, lawyers, human rights defenders, academics, senators.
"I have heard debates between politicians, explanations by government officials, and indeed I have watched footage too of police and military men – and all saying there are other ways; better ways; other options, and better options."
Duterte's government appeared to be caught off guard by Callamard's unannounced trip, and said it would lodge a protest with the United Nations because she had not organised the visit through official channels.
"(In) not contacting our government in advance of this visit, she has sent a clear signal that she is not interested in getting an objective perspective on the issues that are the focus of her responsibility," presidential spokesman Ernesto Abella said in a statement.
Duterte last year invited Callamard to visit the Philippines to investigate the killings, but set strict conditions including a demand that she have a public debate with him on the drug war.
Callamard refused to come under those conditions.
She told reporters in a brief statement on Friday that she did not travel to the Philippines to conduct a UN investigation -- she said she was merely taking part in the academic forum.
However she did meet with various human rights campaigners and lawyers while in the Philippines, including some who organised the forum.
Duterte was elected last year largely on a law-and-order platform in which he promised to eradicate illegal drugs in the Philippines by killing tens of thousands of people.
Since then, police have reported killing 2,692 people in anti-drug operations.
They say unspecified parties have murdered another 1,847 people in drug-related incidents, while 5,691 other violent deaths are under investigation.