Ottawa, July 9 : Canadian Prime Minister Justin Trudeau said that he was concerned about reports that the US was considering reimposing tariffs on Canadian aluminium and possibly steel. Speaking to reporters here on Wednesday, Trudeau said he looked forward to congratulating US President Donald Trump on US-Mexico-Canada Agreement (USMCA) which came into force on July 1, replacing the 26-year-old North American Free Trade Agreement (NAFTA), reports Xinhua news agency. Trudeau did not travel to Washington on Wednesday to attend a meeting with Trump and Mexican President Andres Manuel Lopez Obrador marking the launch of the new trade deal. He told reporters that it's really important that at a time of economic strain and stress, Canada continues to "have access to the world's most important market and this is good for Canadian workers and Canadian jobs right across the country". "At the same time, we are concerned about the threat of extra tariffs on aluminium and possibly steel. "This is something that again is a little difficult to understand because the US relies heavily on imports of Canadian aluminium, in particular, for their domestic manufacturing capacity," he said. Trudeau said the US doesn't produce nearly enough aluminium to be able to cover its needs. Canadian officials are continuing to push very hard on encouraging the US not to move forward on tariffs that don't have any justification and will have a negative impact, the Prime Minister added. Trudeau's remarks came after last month's reports that the US was planning to re-impose a tariff of 10 per cent on Canadian aluminium unless the Ottawa government agrees to limit aluminium exports. Canada's CTV said that the announcement on tariffs was possible in the coming weeks. If the US decides to re-impose tariffs on Canada, it will re-open a trade fight between the two countries that has been healing since similar tariffs were lifted just over a year ago. /IANS