A U.S. Department of Commerce spokesman says the government will announce its decision on Boeing's request for preliminary duties against Bombardier's CSeries on Tuesday, a day later than it previously indicated.

Industry analysts and the Montreal-based company expect preliminary countervailing duties will be imposed on aircraft deliveries to the United States.

Seth Seifman of J.P. Morgan says he assumes some duties will be announced next week but a ruling on whether they will take effect isn't expected until early 2018.

Bombardier (BBDb.TO) said last week that it also expects duties will be imposed short-term but that it will prevail when the final determination is made.

The Canadian government is putting pressure on Boeing (BA.N) to drop its complaint, threatening to cancel plans to buy 18 Boeing Super Hornet fighter jets.

Prime Minister Justin Trudeau has received support from his British counterpart, Theresa May, who wants to protect jobs in Northern Ireland, where the plane's wings are assembled.

Seifman says Boeing was emphatic during an investor conference on Monday that it won't back down despite the prospect of losing business with Canada and CSeries customer Delta Air Lines.