The Canadian government is facilitating the sale of 16 helicopters to the Philippines military, which human rights groups have accused of killing civilians and committing other atrocities while waging a war on two rebel groups.
Duterte said that he can not guarantee that the helicopters will not be used in combat operations in the future.
Bell Helicopter said in an announcement of the deal that the aircraft were intended "for a variety of missions such as disaster relief, search and rescue, passenger transport and utility transport".
News of the sale caused some in Canada to raise concerns over Duterte's human rights record.
"They are not attack or close support aircraft", he said.
According to the Philippine defence department, the deal was signed with trade promotion outfit Canadian Commercial Corp last December, shortly after Trudeau clashed with Duterte during a Manila visit over alleged Philippine police murders of thousands of drug suspects.
Duterte, who has been critical of USA security policies and has lashed out at Washington for criticizing his deadly crackdown on illegal drugs, did not elaborate on why he wants purchases of unspecified US arms to be stopped. Freeland's office also circulated a photo of a similar helicopter painted red, blue and white.
Reuters earlier quoted Padilla as saying "The helicopters will be used for the military's internal security operations", implying they might be used for counterinsurgency operations.More news: NASA spacecraft captures farthest images away from Earth
The Philippine military is keen to boost its capabilities as it fights Communist insurgents and Islamic extremists.
Known for his impromptu decisions and public outbursts, the Philippine president declared in a nationally televised news conference that he wants the helicopter deal, and purchases of unspecified USA weapons, halted. Other uses would be for disaster relief.
"I want to tell the armed forces to cut the deal, don't proceed anymore and somehow we will look for another supplier".
Duterte also hinted that Canada should no longer expect the Philippines' help in times of trouble as long as he is president.
Known for his impromptu decisions and public outbursts, Duterte declared in a nationally televised news conference in southern Davao city, his hometown, that he wants the helicopter deal, along with purchases of unspecified USA weapons, halted.
"We respect their values".
The helicopters are scheduled to be delivered to the Philippines starting the first quarter of next year.