The United States filed a second formal trade complaint against Canada on Wednesday over Ottawa's dairy import policies, which Washington says harms American producers.

Washington has requested dispute settlement consultations under the U.S.-Mexico-Canada Agreement (USMCA), saying the changes to the dairy quota system which Ottawa announced last week do not resolve the long-standing complaints and violate the trade agreement.

The policy continues to "prevent U.S. workers, producers, farmers and exporters from getting the full benefit of the market access that Canada committed to under the USMCA," U.S. Trade Representative Katherine Tai said in a statement.

Canada's policies limit a large share of American dairy exports, including milk, butter, yogurt and ice cream, to Canadian processors under a system known as tariff rate quotas (TRQs), which U.S. officials say restrict market access for U.S. producers.

(Cover: Cows stand in a barn while being milked at a dairy farm in South Mountain, Ontario, Canada, June 29, 2018. /Reuters)