MANILA - United Nations special rapporteur Agnes Callamard on Saturday snubbed criticism of her visit to Manila, where she attended an academic forum on drug policies.

"I'm used to it," Callamard told reporters on the sidelines of the forum at the University of the Philippines in Diliman.

Palace officials earlier slammed the UN Special Rapporteur on extra judicial, arbitrary and summary killings for her alleged "unannounced visit."

The Palace later clarified that they were informed of Callamard's unofficial trip to Manila, but said that it "was neither timely nor proper courtesy accorded to a sovereign nation."

Callamard's Wikipedia page was also defaced Friday, a day after she made her first public appearance in Manila at the 30th anniversary of the Commission on Human Rights.

"It's a pity because the purpose of the forum is to open avenues of dialogue to provide expertise about the drug abuse in the country... That should be the focus, not me," Callamard said.

The UN special rapporteur first earned the ire of President Rodrigo Duterte and his supporters after she expressed intent to investigate alleged human rights violations committed under the government's war on drugs.

She said she would push through with her mission if government lifts conditions she had rejected, including a public debate with President Duterte.