US Secretary of State Antony Blinken has urged India to cooperate with Canada in the investigation related to the death of Khalistani leader Hardeep Singh Nijjar, an incident which has triggered a diplomatic standoff between Ottawa and New Delhi.

Blinken said the US is 'deeply concerned' about the allegation raised by Trudeau over the death of the Khalistani leader.

"We are deeply concerned about the allegations that Prime Minister Trudeau has raised," Trudeau told reporters.

He said: "We have been consulting throughout very closely with our Canadian colleagues – and not just consulting, coordinating with them – on this issue."

"From our perspective, it is critical that the Canadian investigation proceed, and it would be important that India work with the Canadians on this investigation," he said.

"We want to see accountability, and it’s important that the investigation run its course and lead to that result," Blinken said.

He made the comments at a time when Indian External Affairs Minister S Jaishankar will be visiting the US to attend the 78th United Nations General Assembly.

During his visit, he is also scheduled to meet US Secretary of State Antony Blinken.

The ongoing India-Canada tensions continued to simmer as Canadian PM Justin Trudeau has reiterated his allegations on India's role in the killing of Khalistani separatist leader Hardeep Singh Nijjar in June in British Columbia, claiming that there are 'credible reasons' to believe in the same.

Addressing a press conference at Canada's Permanent Mission to the United Nations in New York, Trudeau was quoted as saying by media: "As I said on Monday, there are credible reasons to believe that agents of the Government of India were involved in the killing of a Canadian on Canadian soil."

He said: "There is something of utmost foundational importance in a country's rule of law in a world where international rules-based order matters."

He asked the Indian government to 'work' with Canada to ensure full transparency and accountability in the matter.

While New Delhi outrightly rejected Trudeau's allegation, calling it "absurd" and "motivated", the relations between the two countries have worsened with Canada and India expelling a senior diplomat each.

India has also issued a travel advisory for Indian nationals, particularly students, in Canada and also those contemplating travel to the North American country, asking them to exercise utmost caution.

Who was Hardeep Singh Nijjar?

Hardeep Singh Nijjar, a Canada-based pro-Khalistan leader, was shot dead in Surrey city, British Columbia province in June.

He had been a leading figure in the Khalistan separatist movement and was closely associated with Sikhs for Justice (SFJ).

Nijjar was also serving as the president of Guru Nanak Sikh Gurdwara in Surrey.

Nijjar, a member of the Khalistan Tiger Force (KTF), was a ‘wanted terrorist’ for his involvement in various acts of violence and subversive activities.