The leaders of Canada and Mexico, the United States’ two largest trading partners, will meet on Thursday — without their U.S. counterpart — after eight months of chaotic trade talks and threats of tariffs.

The talks, between Prime Minister Mark Carney of Canada and President Claudia Sheinbaum of Mexico, are expected to focus on trade, as well as investments in areas like mining, agriculture and natural gas.

Both leaders will also discuss preserving their free trade partnership with the United States, which has so far limited the effect of President Trump’s tariffs on their economies. On Tuesday, the three countries opened public consultations on the trade pact, the U.S.-Mexico-Canada Free Trade Agreement, or the U.S.M.C.A., the first step in a review of the agreement.

Mr. Carney and Ms. Sheinbaum are also likely to exchange notes on strategies for dealing with Mr. Trump, whose policies toward Canada and Mexico have differed despite both countries’ deep economic ties to the United States.

The Trump administration has imposed steep tariffs on some exports from Canada, which has been one of the few countries along with China to retaliate against U.S. trade measures.