(CNN) A Canadian man murdered by militants in the Philippines has been described as a "kind and gregarious person who touched everyone he knew with his enthusiasm and generosity."

John Ridsdel was beheaded by Islamist militant group Abu Sayyaf , which took him hostage along with three others in September last year.

"Our family is devastated at the loss of our father and brother John Ridsdel whose life was cut tragically short by this senseless act of violence."

Bob Rae, a close friend of Ridsdel said that "lots of effort" was made to respond to ransom demands but the amounts asked for were too high.

A former Canadian Member of Parliament, Rae told CNN that he "was a very vital and engaging guy."

Ridsdel had worked as a reporter for The Calgary Herald and CBC and eventually retired from TVI Pacific to tour the world.

"He was very adventurous, his career path was unique to him," Rae said.

'Cold-blooded murder'

Speaking on Monday, Canadian Prime Minister Justin Trudeau said Ridsdel's death was "an act of cold-blooded murder and responsibility rests squarely with the terrorist group who took him hostage."

Trudeau said Canada condemns the "brutality" of this "unnecessary death," and expressed his "deepest condolences" to Ridsdel's family and friends.

We are outraged by the cold-blooded murder of Canadian John Ridsdel at the hands of terrorists. Full statement: https://t.co/2ZKpScKN7F — Justin Trudeau (@JustinTrudeau) April 25, 2016

Philippines security forces vowed that "the full force of the law will be used to bring these criminals to justice."

"There will be no let up in the determined efforts ... to neutralize these lawless elements and thwart further threats to peace and security," the Armed Forces of the Philippines and the Philippine National Police said in a joint statement.

Other hostages

Ridsdel was among four people abducted September 21 at the Oceanview Resort on Samal Island, which lies off the coast of the major southern island of Mindanao, Philippine officials said

This part of the southern Philippines is home to Abu Sayyaf, an Islamist militant group that's been linked to al Qaeda and ISIS . The separatist group has at times preyed on foreigners in recent years, taking them hostage to further its aims.

Hostages Robert Hall and Marites Flor

The situation has drawn growing political attention in the country. Earlier this month, one lawmaker called for Abu Sayyaf to be a topic in the country's next presidential debate.

In addition to Ridsdel, Norwegian national Kjartan Sekkingstad, Canadian national Robert Hall and Filipina Marites Flor were also taken hostage, according to officials

In a statement , Norwegian Foreign Minister Borge Brende said Norway would "continue our ongoing efforts to find a solution for the remaining hostages."

Negotiations

One of the masked men in the video had threatened to "do something terrible against these captives" if the captors' demands -- which included ransom -- were not met.

Rae, who was involved in negotiations, told CNN that "lots of effort" was made by the families to respond to the group's ransom demands, but the figures asked for were too high.

JUST WATCHED Canadian hostage John Ridsdel killed in the Philippines Replay More Videos ... MUST WATCH Canadian hostage John Ridsdel killed in the Philippines 01:20

"The numbers being bandied about were in the millions and millions of dollars and none of the families involved had that kind of cash."

The Philippine government maintains a no-ransom policy , and the Canadian and Norwegian governments "were not going to pay ransom," Rae said.

"These poor people ... were caught in a maelstrom."

Rommel Banlaoi, executive director at the Philippine Institute for Peace, Violence and Terrorism Research, said that the killing would help boost Abu Sayyaf's leverage.

"The group showed that it does not bluff and does not merely strike fear. They showed that they have the capacity for violence if their demands are not met."

Banlaoi added that money has been a motivator for the group's activities.

"Their motivation is money, so that they could generate funds to buy the loyalty of local communities."