President Donald Trump said the US will put a 35% tariff on some imports from Canada, escalating the tensions between two countries that have impaired one of the world’s largest trading relationships.

The imbalance in President Trump’s treatment of America’s closest trading partners may come from his desire to make Canada the 51st state, some Canadians believe.

U.S. President Donald Trump on Thursday signed an executive order increasing tariffs on Canadian goods to 35% from 25% on all products not covered by the U.S.-Mexico-Canada trade agreement, the White House said.