Washington, Dec 6 : The US has said that it is looking forward to seeing the results of India's investigation into the plot to kill a Sikh separatist leader, and will not make any assessments before the probe is finished. "We have noted at the most senior levels of this government -- the Secretary of State has raised this directly with his foreign counterpart that we take this issue very seriously. They told us they would conduct an investigation," US State Department spokesperson, Matthew Miller, said in his news briefing on Tuesday. "They have publicly announced an investigation. And now we'll wait to see the results of the investigation, but it's something we take very seriously," Miller said in response to a question on developments in the case at the diplomatic level. He further said that it would be "inappropriate" for him to comment on a "law enforcement matter" as the Department of Justice is presenting the case in court. "We are looking forward to seeing the results of that (India's) investigation, and I'm not going to make any assessments, obviously, before the investigation itself is completed," Miller told reporters. The comments come a week after the White House said that it takes the allegations that an Indian was involved in a foiled bid to kill Khalistani leader Gurpatwant Singh Pannun on its soil "very seriously". When asked by a reporter whether the plot to kill Pannun is an attack on the US sovereignty, Miller said: "I'm not going to speak beyond what -- the information that's contained in an indictment for I think what are -- for what I think are fairly obvious reasons". US federal prosecutors last month accused Indian intelligence official Nikhil Gupta of "planning and directing" a plot from India to allegedly kill Pannun in New York. Reacting to the charges, India's Ministry of External Affairs said it was a 'matter of concern' and 'contrary to Indian government's policy'. India constituted a high-level Enquiry Committee to look into all the relevant aspects of the matter, and said it will take necessary follow-up action based on the findings of the Committee. On being asked about India's 'non-cooperation' with the Canadian government on Khalistani leader Hardeep Singh Nijjar's case, Miller said in his Tuesday's briefing they have urged New Delhi to cooperate with Ottawa. Canada claimed in September that Nijjar was shot dead by Indian agents in British Columbia province in June this year. While responding to Canada's allegations, India said recently: "As far as Canada is concerned, they have consistently given space to anti-India extremists and violence. That is at the heart of the issue". /IANS