Washington, Sep 19 : The US has expressed "deep concern" over Canadian Prime Minister Justin Trudeau's allegations of "potential link between Indian government agents and murder of Khalistan Tiger Force chief Hardeep Singh Nijjar". According to a report in ABC NEWS, White House National Security Council spokesperson Adrienne Watson in a statement said, "We are deeply concerned about the allegations referenced by Prime Minister Trudeau earlier today." "We remain in regular contact with our Canadian partners. It is critical that Canada's investigation proceed and the perpetrators be brought to justice," the statement said. The startling accusation was followed by the Canadian foreign minister Melanie Joly, who informed that they had expelled a top Indian diplomat over the incident. Joly said Trudeau had also raised the matter with US President Joe Biden and UK Prime Minister Rishi Sunak. India rejected claims by the Canada government that it had an involvement in the killing of Nijjar. Terming them as "absurd and motivated" the external affairs ministry in a statement said, "We have seen and reject the statement of the Canadian Prime Minister in their Parliament, as also the statement by their Foreign Minister. Allegations of Government of India's involvement in any act of violence in Canada are absurd and motivated." "Similar allegations were made by the Canadian Prime Minister to our Prime Minister, and were completely rejected," the statement said further. "We are a democratic polity with a strong commitment to rule of law," the ministry said further. "We urge the Government of Canada to take prompt and effective legal action against all anti-India elements operating from their soil," the strongly worded statement added. It went on to add, "The inaction of the Canadian Government on this matter has been a long-standing and continuing concern". India's reaction came after Canadian Prime Minister Trudeau in an emergency statement made in Parliament, said on Monday that Canadian security agencies have been actively pursuing "credible allegations of a potential link between Indian government agents and the murder of Khalistan Tiger Force chief Hardeep Singh Nijjar in British Columbia in June". Amid deteriorating diplomatic relations between India and Canada, New Delhi on Tuesday expelled a senior Canadian diplomat based here, who has been asked to leave within the next five days, citing interference concerns. /IANS