OTTAWA -- New details are emerging about the high-level, backroom wrangling around Boeing Co.'s dispute with Bombardier, which is quickly becoming an international dog fight.

The Trudeau government revealed Tuesday that it held secret talks with Boeing in hopes of convincing the U.S. aerospace giant to drop its case against Bombardier at the U.S. Commerce Department.

The revelation came amid word the British government has been lobbying U.S. officials in support of Bombardier, which employs about 5,000 people at an aerospace manufacturing plant in Northern Ireland.

That includes a call on Sept. 5 to President Donald Trump from British Prime Minister Theresa May, who will likely discuss the dispute with Prime Minister Justin Trudeau when she visits Canada next week.

"This is a commercial matter, but the U.K. government is working tirelessly to safeguard Bombardier's operations and its highly skilled workers in Belfast," said a British government spokesperson.

"Ministers across government have engaged swiftly and extensively with Boeing, Bombardier, the U.S. and Canadian governments. Our priority is to encourage Boeing to drop its case and seek a negotiated settlement with Bombardier."

Speaking in St. John's, N.L., Foreign Affairs Minister Chrystia Freeland said Canadian and British officials "are as one" when it comes to supporting Bombardier in its dispute with Boeing.

News of the secret talks between Canada and Boeing, as well as the U.K.'s surprise involvement, highlight the broad scope and importance of the dispute, which until now has gone largely overlooked.

Yet the moves, which follow Liberal threats to scrap the planned purchase of 18 "interim" Super Hornets from Boeing because of the dispute, appear to have done little to resolve the matter.

Like the British, Canada had hoped to convince Boeing to drop its complaint that Bombardier is selling its CSeries jets at an unfairly low price to Delta Airlines with help from government subsidies.

But the Liberal government's talks with Boeing broke down last month when, according to Canada's ambassador to the U.S., David MacNaughton, the company decided to stop negotiating.

"We had some proposals back and forth and then they walked away," MacNaughton said in St. John's, where federal cabinet ministers were meeting to strategize before the return of Parliament next week.

"For whatever reason, they (Boeing) decided they weren't going to continue to have discussions with us."

The U.S. Commerce Department is currently investigating Boeing's complaint and could impose tariffs or fines on Bombardier if it finds against the Canadian company.

It is expected to release its preliminary findings on Sept. 25.

Canadian and British officials aren't the only ones to put pressure on Boeing and the Trump administration, as a handful of U.S. members of Congress have also come out in support of Bombardier.

Trudeau also waded into the fray last week, when he called the governor of Missouri, where Boeing makes its Super Hornet fighter jets, to complaint about the company.

Boeing released a statement Tuesday saying it "had to take action as subsidized competition has hurt us now and will continue to hurt us for years to come.

"Global trade only works if everyone plays by the same rules of the road," it added, "and that's a principle that ultimately creates the greatest value for Canada, the United Kingdom, the United States, and our aerospace industry."