MEXICO CITY/WASHINGTON/OTTAWA (Reuters) - Mexican and Canadian officials are increasingly frustrated by tariff negotiations with the Trump administration, with a lack of clarity over exactly what the U.S. wants making any resolution seem impossible, sources from both countries told Reuters.

After implementing across-the-board 25% tariffs on goods from Canada and Mexico earlier this week, President Donald Trump on Thursday announced a one-month reprieve for Mexico with an exemption for the North American auto sector also in the works. On Thursday, just after midday Eastern Time, tariffs remained in place for Canada. 

The on-again, off-again tariffs and the high-level discussions surrounding them have exasperated negotiating teams, according to three Mexican officials and two Canadian sources familiar with negotiations.

It's like "dealing with an angry partner and you don't know what they're mad about," one Mexican official. "It's not clear what they want."

The press person for Mexican President Claudia Sheinbaum responded to a request for comment by directing Reuters to Sheinbaum's public comment on Thursday. In a post on X, Sheinbaum said: "We had an excellent and respectful call," that respected the "sovereignties" of both countries.

Canadian Prime Minister Justin Trudeau's office and the White House both did not immediately respond to requests for comment. 

Trump based the legal justification for the tariffs on combating fentanyl and illegal immigration, but he and others in his administration often expand the justification to include trade deficits and protecting U.S. industries like autos and lumber.

Despite the shared frustration of Mexico and Canada, the two countries have taken distinct tones in public. Sheinbaum has stressed her respect for Trump and the close cooperation with the U.S. Canada has bluntly criticized the chaos.

Trudeau on Thursday said Canada will be in a trade war with the United States for "the foreseeable future." U.S. Treasury Secretary Scott Bessent called Trudeau "a numbskull."

Trudeau's foreign minister has been even franker.

"We won't get through this, another psychodrama every 30 days," Foreign Minister Melanie Joly told business leaders in Toronto earlier this week. 

"The problem we've had is it's not clear what the American president wants," she added. "I've had conversations with colleagues in Washington saying, 'Okay, but at the end of the day, what do you guys want?' And I got the answer, 'We're about to know.' There's one decision maker in the system. He's the only one to know."  

U.S. Commerce Secretary Howard Lutnick dismissed the idea that he didn't know what Trump wants as "fake news" and "so silly" in an interview on Thursday with CNBC.

Trump "calls everybody all the time," Lutnick said. "I speak to him all the time. You've got to be kidding me. The president knows exactly what he wants. We know exactly what he wants." 

But Canadian and Mexican officials said the lack of clarity over demands as well as uncertainty over whether Trump administration officials in bilateral meetings were actually able to deliver on what they said was making discussions incredibly challenging. 

The scope of negotiations is not clear, they said, with talks sometimes seeming to be focused on fentanyl and at other times on migration, while on some occasions the focus seemed to be trade deficits.

"The U.S. reasons for the tariffs constantly shift," said another Mexican official. "If we can't identify the problem, we can't identify the solution."