TORONTO – Canada’s new ambassador to the United States said Thursday that resolving a decades-long lumber dispute with Washington would be his first priority, and he predicted a new tone in relations between the neighbors.

The Bush administration began imposing antidumping duties against Canadian lumber in 2002. Canadian lumber exporters have paid more than $4.3 billion in duties so far. Canada insists the tariffs are unfair.

The dispute has fueled talk of a trade war between the world’s largest trading partners. Canada and the United States conduct some $1.6 billion in trade across their shared border each day.

Michael Wilson, confirmed Thursday as the new envoy to Washington, said sorting out the contentious issue starts at the top with the new prime minister, Stephen Harper.