WASHINGTON — Justin Trudeau, the prime minister of Canada, is to meet with President Obama on Thursday for the first official visit by a Canadian leader in 19 years, a diplomatic honor made possible in part by new pledges of cooperation on combating climate change.

Mr. Obama and Mr. Trudeau are expected to announce new commitments to reduce planet-warming emissions of methane, a chemical contained in natural gas that is about 25 times as potent as carbon dioxide, and which can leak from drilling wells and pipelines.

That announcement will come during a day of ceremony that will conclude with a state dinner in the East Room of the White House. On the menu is Alaskan halibut “casseroles,” roasted apricot galette, baby lamb chops with Yukon Gold potato dauphinoise and a maple pecan cake with cocoa nib wafer and butterscotch swirl ice cream.

The arrival of Mr. Trudeau and his wife, Sophie Grégoire Trudeau, has prompted comparisons to a similar visit in 1977 by Pierre Trudeau, a former prime minister and the current leader’s father. That visit made headlines when Margaret Trudeau, the prime minister’s wife, wore a short dress that fell just below the knee to the White House state dinner.