By Neil Jerome Morales

MANILA (Reuters) - The Philippines is stepping up President Rodrigo Duterte's battle on drugs with incoming college freshmen set to face tests for illegal drug use from next year, an education official said on Friday.

A wave of 2,400 killings unleashed in a war on drugs since Duterte came to power two months ago has gained popular support in the Southeast Asian nation, but has alarmed the United Nations and the United States, Manila's close ally.

The government seeks to make drug testing a requirement for all incoming college students, said Julito Vitriolo, the executive director of the Commission on Higher Education.

"This was born out of the president's call to make campuses drug-free, because we see the pervasive effects of drug use," he said in a television interview.

"What's important is for students not to use drugs. It will be a deterrent if they want to continue their studies," Vitriolo said, adding that those testing positive could go through rehabilitation before being admitted to college.

Drug testing for university admission is now done on a voluntary basis.

"It is something that we should be doing because the drug menace is real," Monico Jacob, president of STI Education Systems Holdings Inc, told Reuters, referring to compulsory tests.

STI, which has more than 103,000 students this academic year, has performed mandatory drug testing for the past five years.

Duterte won the May election by a landslide on a promise to wipe out drugs and dealers. He has named politicians, police generals and judges linked to the drug trade.

Police data show 2,400 deaths in the drug war after Duterte took over, a toll police say is a result of drug dealers resisting arrest or gang feuds.

(Reporting by Neil Jerome Morales; Editing by Clarence Fernandez)