Prime Minister Justin Trudeau will not join his North American counterparts in Washington, D.C., this week to celebrate the coming into force of the three countries' renegotiated trade pact.

"While there were recent discussions about the possible participation of Canada, the prime minister will be in Ottawa this week for scheduled cabinet meetings and the long-planned sitting of Parliament," Chantal Gagnon, a spokesperson for the Prime Minister's Office, said in a statement.

"We're obviously concerned about the proposed issue of tariffs on aluminum and steel that the Americans have floated recently," he said, in reference to a statement last month by Trump that he may look at reintroducing tariffs on Canadian aluminum.

tariffs on steel and aluminum in 2018 led to a nearly yearlong trade spat, with Canada levying retaliatory tariffs on U.S.

The NAFTA file had been in Chrystia Freeland's hands since Trump first demanded the trade pact be reopened. ​As foreign affairs minister, ​Freeland spent months shuttling back and forth between Ottawa and Washington in 2018 and 2019, and continued to oversee the deal even after being named deputy prime minister after the election last October.

A June 29 Order in Council passed that responsibility to International Trade Minister Mary Ng, as outlined in the legislation to implement the deal.