The U.S. and U.K. governments are calling on the Indian government to rescind its push to reduce the presence of Canadian diplomats in its country and “uphold” its obligations under international law.

The Canadian government announced on Thursday that it pulled 41 of its 62 diplomats from India after New Delhi made a request for diplomatic parity in the two countries by Oct. 10.

Foreign Affairs Minister Melanie Joly said in their “unreasonable” request for diplomatic parity, India would only allow 21 Canadian diplomats and their families to maintain their diplomatic status in that country, leaving others stripped of diplomatic immunity and vulnerable to reprisal or arrest.

Officials from the United States and U.K. expressed their concerns with the recent development on Friday.

“We are concerned by the departure of Canadian diplomats from India, in response to the Indian government’s demand of Canada to significantly reduce its diplomatic presence in India,” U.S. Department of State spokesperson Matthew Miller said in a statement issued Friday.

“Resolving differences requires diplomats on the ground. We have urged the Indian government not to insist upon a reduction in Canada’s diplomatic presence and to co-operate in the ongoing Canadian investigation.”

Miller added that the United States expects India to “uphold its obligations” under the 1961 Vienna Convention on Diplomatic Relations, “including with respect to privileges and immunities enjoyed by accredited members of Canada’s diplomatic mission.”

The U.K.’s Foreign, Commonwealth & Development Office (FCDO) shared similar concerns, saying it “does not agree with the decisions taken by the Indian government” that have resulted in a number of Canadian diplomats departing India.

“We expect all states to uphold their obligations under the 1961 Vienna Convention on Diplomatic Relations,” an FCDO spokesperson said in a statement released Friday.

“The unilateral removal of the privileges and immunities that provide for the safety and security of diplomats is not consistent with the principles or the effective functioning of the Vienna Convention.”

Joly has also accused India of acting "contrary to international law" and in violation of the Vienna Convention on Diplomatic Relations.

On Friday, Prime Minister Justin Trudeau echoed those comments.

“This is them choosing to contravene a very fundamental principle of international law and diplomacy," Trudeau said Friday in Brampton, Ont.

“It is something that all countries in the world should be very worried about."

On the other hand, the Indian government rejected that it had violated international law in asking Canada to withdraw its diplomats so that both governments have roughly the same number working in each country.

"We reject any attempt to portray the implementation of parity as a violation of international norms," India's Ministry of Foreign Affairs said in a statement Friday.

The comments come in the wake of a diplomatic dispute between India and Canada, which crystalized last month when Trudeau accused the Indian government of having a role in the June killing of prominent Canadian Sikh leader Hardeep Singh Nijjar in B.C.

Trudeau said at the time that intelligence agencies were investigating “credible allegations” about Nijjar’s murder on Canadian soil, which India has adamantly denied.

Federal law enforcement agencies in Canada are “working actively” to investigate the murder and officials have made calls for India to co-operate, Joly and Trudeau have said.

David Cohen, the United States ambassador to Canada, previously told CTV News that there was “shared intelligence among Five Eye partners” that informed Trudeau’s public allegation of the Indian government’s role in the Sikh separatist leader’s death.

Cohen added that there was “a lot of communication between Canada and the United States about this,” without getting into specifics.

- With files from CTV News Senior Digital Parliamentary Reporter Rachel Aiello, The Canadian Press and The Associated Press