Prime Minister Justin Trudeau has received an apology from Filipino president-elect Rodrigo Duterte for the killing of Canadian hostage John Ridsdel.

Duterte, the long-time mayor of southern Davao, told reporters he apologized for last month's beheading of hostage John Ridsdel when Trudeau called Tuesday to congratulate him for his election victory.

"I said 'Mr. Prime Minister, please accept my apologies for the incident,"' Duterte told reporters in Davao. "We will try our very best and see to it that nothing of this sort will happen again, and you can rest assured that when the time comes, we will be able to apprehend the criminals and exact justice."

The militants had been asking for a ransom payment in exchange for Ridsdel's release before he was beheaded last month.

Another Canadian, Robert Hall, was kidnapped by the same group and is still being held hostage in the Asian country.

Human rights discussed

Trudeau is in Japan for a Group of Seven summit where he is expected to try to encourage Canada's partners to join Ottawa in refusing to pay ransoms to kidnappers.

Duterte said he and Trudeau also discussed human rights, and he said he told Trudeau: "Universal Declaration of Human rights, fine, I said 'I'm following it, but Mr. Prime Minister, with few exceptions."'

Duterte has been criticized for his human rights record in Davao, where he was mayor for 22 years. Hundreds have been killed in that port city on an anti-crime purge. On the presidential campaign trail, Duterte repeatedly vowed to kill drug criminals.

No details from PMO

A spokesman for Trudeau confirmed that the prime minister spoke with Duterte, but declined to offer details of the call.

Cameron Ahmad says the Canadian government won't comment or release any information that could compromise ongoing efforts or endanger the safety of the remaining hostages.

Ahmad says the government's first priority is the safety and security of its citizens.

Canadian hostages Robert Hall John Risdel Oct 15 2015

The status of Canadian Robert Hall (left), seen in a video uploaded to YouTube, is unknown. John Ridsdel (middle) was executed by Abu Sayyaf in late April. (Site Intelligence Group/YouTube)

The militants released a video showing Ridsdel's beheading, an American group that monitors jihadi websites said after his killing.

Ridsdel, 68, of Calgary, was one of four tourists — including Hall, Norwegian Kjartan Sekkingstad and Filipina Marites Flor — who were kidnapped last Sept. 21 by Abu Sayyaf militants.

Ridsdel beheaded due to 'non-compliance'

In a series of tweets, Rita Katz of the SITE Intelligence Group cited the video as saying Ridsdel was beheaded on April 25 "due to non-compliance" of the Canadian government.

Ridsdel was beheaded after Abu Sayyaf militants made a large ransom demand, reportedly over $8 million Cdn for his release.

Trudeau has said Canada would never pay ransom for the release of hostages.

"Paying ransom for Canadians would endanger the lives of every single one of the millions of Canadians who live work and travel around the world every single year," Trudeau said earlier this month.

RCMP investigates

A senior official said at the time that the RCMP was conducting a criminal investigation into Ridsdel's murder.

Philippines Duterte

Rodrigo Duterte seen in a May 9 press conference in Davao city in southern Philippines, said authorities are determined to bring the militants to justice for John Ridsdel's death. (Bullit Marquez/The Associated Press)

The official, who spoke on condition of anonymity given the sensitivity of the ongoing hostage case, said the Mounties were relying on the extraterritorial provisions of the Criminal Code to pursue the overseas investigation.

The two Canadians, Sekkingstad, who is a permanent resident of Canada, and the Filipina woman were snatched from a marina.

Ridsdel's body was found by villagers beside a dry creek in a mountain near Talipao town in Sulu province.

With files from The Associated Press