The US Justice Department said that a 52-year-old man worked with an Indian govt employee, whose responsibilities included security and intelligence, on the plot to assassinate a New York City residen

The remarks by Trudeau came after Nikhil Gupta, 52, was charged on Wednesday with murder-for-hire in connection with his participation in a foiled plot to assassinate a US citizen in New York City.

Following Canadian Prime Minister Justin Trudeau's recent call for India's cooperation in the investigation of the killing of India-designated terrorist Hardeep Singh Nijjar, former diplomat TP Sreenivasan said that India is not involved in such activities.

The charges are rooted in a decades-old dispute over the demand by some Sikhs for a sovereign state known as Khalistan carved out of northern India.

The US indictment, unsealed Wednesday, accuses Indian citizen Nikhil Gupta and an unnamed Indian govt employee of conspiring to assassinate Sikh separatist Gurpatwant Singh Pannun.