President Trump welcomes Canadian Prime Minister Justin Trudeau to the Oval Office for talks Thursday. (Oliver Contreras/For The Washington Post)

President Trump, hosting Canadian Prime Minister Justin Trudeau at the White House on Thursday, promised to help Ottawa in its tense diplomatic standoff with China and spoke optimistically about the prospects for the ratification of the new United States-Mexico-Canada trade pact.

At an Oval Office meeting between the leaders, Trump said he would raise the detention of two Canadians in China with President Xi Jinping when they meet at a Group of 20 meeting in Japan next week.

“Anything I can do to help Canada, I will be doing,” he said. 

Canadian officials have expressed frustration over what they have seen as insufficient American support after Canadian authorities arrested Huawei executive Meng Wanzhou in Vancouver, B.C., on U.S. charges. After Meng’s arrest, China detained the two Canadians and blocked some Canadian agricultural imports. 

The meeting Thursday was a striking change of tone from a meeting this time last year. That meeting, at a Group of Seven summit in Quebec, ended with the U.S. leader lambasting the prime minister from his airplane in a series of not-so-neighborly tweets.

But with the clock ticking on the ratification of the new trade agreement, the conflict with China heating up and both leaders looking ahead to elections, Trump’s tone has softened significantly — and Trudeau seems willing to look past the insults of yesteryear. 

With cameras rolling, Trump said it was an “honor” to host Trudeau, whom he called “my friend.” The Canadian leader nodded politely.

In a statement after the meeting, Trudeau called the discussions “productive and far-

“I look forward to building on the progress we made today at next week’s G-20 summit in Osaka,” he said.

The apparently drama-free afternoon felt like a possible reset.

“This is an effort to return to the norm in U.S.-Canada relations,” said Eric Miller, the trade specialist who runs the ­Washington-based Rideau Potomac Strategy Group.

The new message, Miller said, is a move away from Canada vs. the United States and back to “Canada and the U.S. vs. the world.”

It helps that Trump and Trudeau focused on two interlocking issues — trade and China — that are front of mind for both.

After more than a year of gloves-off negotiations over the trade agreement formerly known as NAFTA, both leaders are eager to close the deal.

Trump’s decision last month to lift tariffs on Canadian and Mexican steel and aluminum paved the way for the agreement. Mexico on Wednesday became the first country to ratify the deal, known as USMCA.

But before Trudeau calls lawmakers back from summer holiday to work on the USMCA, he wanted to know how ratification is progressing on the U.S. side. Congressional approval of the deal, a Trump policy priority, is still in question; the president will need backing from Democrats.

After months of political stalemate, his administration is now working on a deal to get those Democrats on board. U.S. Trade Representative Robert E. Lighthizer told a Senate hearing Tuesday that he is hoping for “substantial progress” this week. 

“I look forward to working with members to make [the agreement] even better and to write implementing legislation that will earn large, bipartisan support,” Lighthizer said. “We’re on track.”

Trump echoed that sentiment Thursday, saying he believes ratification is possible and urging House Speaker Nancy Pelosi (D-Calif.) to do “the right thing” by approving the pact.

Pelosi and other Democrats have raised questions about several parts of the deal, with particular concern about environmental and labor standards.

“Some of the concerns focus on enforcement,” said former commerce secretary Gary Locke, who now co-chairs the Pass USMCA Coalition, a group of trade associations and businesses. “I know they hope to have in-depth conversations with Lighthizer on this.”

Locke said he was hopeful the deal would move forward.

“The administration is not trying to jam this through Congress,” he said. “Instead, you have [Lighthizer] meeting with Congress and working groups to make sure they heard. I think that’s a good sign.”

Trudeau called his Thursday discussions with Pelosi “frank” and “positive” but did not provide much by way of details. In a brief exchange before the news media, Pelosi and Trudeau settled a wager over the recent NBA finals (the Toronto Raptors, Canada’s only team, defeated the Golden State Warriors, Pelosi’s hometown squad).

Trump’s comments regarding the detained Canadians will be cheered in Ottawa. The arrest of Huawei’s Meng in December has put Canada in a tough spot with Beijing.

The two Canadians that China arrested in what is widely seen as retaliation have been languishing in detention centers since December.

China already has taken aim at Canada’s economy, blocking imports of canola and warning of more to come if Meng isn’t released.

Trudeau, pressed by reporters after the meeting on what, specifically, Trump told him he would do when talking with Xi, offered few concrete details.

“We expect the topic of the Canadians being arbitrarily detained to be on the agenda,” he said.

Asked whether Trump might cancel the U.S. extradition request as part of a deal with China, Trudeau dodged, saying only that Canada is committed to the rule of law and would honor its extradition agreements with the United States.

It’s not clear how committed Trump is to assisting the detained Canadians.

A Canadian readout from the meeting mentioned Trump’s support for them. The statement from the White House did not, referring instead to “shared goals of advancing democracy and defending human rights in the Western Hemisphere” and “the importance of upholding the rule of law and holding China accountable for its unfair economic activities.”

Miller, the trade consultant, ventured that when Trump meets Xi the conversation will probably be focused on trade. But the fact that the president mentioned the case at all still sends a strong signal to the Chinese side. 

Laura Dawson, director of the Canada Institute at the Wilson Center, said Canada’s best bet is to appeal to Trump’s skill as a dealmaker — the dealmaker — who can get China to back off the Canadians for a bit.

“It’s something that is possible from the president,” she said, “a buddy-helping-a-buddy-type intervention.”