AMSTERDAM (Reuters) - The International Criminal Court may have the jurisdiction to prosecute perpetrators of thousands of alleged extrajudicial killings in the Philippines' crackdown on drugs, a prosecutor at the Hague-based tribunal said.

Nearly 2,300 people have died since Duterte started the campaign on June 30, according to police, of which 1,566 were drug suspects killed in police operations.

"I am deeply concerned about these alleged killings and the fact that public statements of high officials of the republic of the Philippines seem to condone such killings," ICC Prosecutor Fatou Bensouda said in a statement.

The Philippines joined the ICC in November 2011 and extrajudicial killings could be prosecuted by the ICC if they are "committed as part of a widespread or systematic attack against a civilian population," she said.

Earlier on Thursday, Philippine President Rodrigo Duterte called U.S. President Barack Obama, the European Union and United Nations "fools" and said he would humiliate them if they questioned his war on drugs.

Duterte's communications secretary, Martin Andanar, said the president has already stated he was "willing to submit himself for investigation before any body".

Andanar said vigilante killings were not sanctioned by the government.

"Many of those who died were killed during legitimate police operations, which are currently undergoing investigation as directed by the president," he said in a statement on Friday.

The ICC, established under the 1998 Rome Statute, is a court of last resort. It only intervenes if a country is found to be unwilling or unable to prosecute crimes under its statute, including war crimes, crimes against humanity and genocide.

(Reporting by Stephanie van den Berg; Additional reporting by Karen Lema in Manila; Editing by Sam Holmes)