WASHINGTON - Canadian Prime Minister Justin Trudeau and President Donald Trump met at the White House on Thursday for talks on the revamped North American trade deal, the conflict with China, and the status of the rather bruised U.S.-Canada alliance.

In remarks at the Oval Office, Trump said they would discuss the push to ratify the U.S.-Mexico-Canada Trade Agreement, expressing confidence that the U.S. would eventually ratify the deal. He also called on House Speaker Nancy Pelosi to "do the right thing" by approving it.

Asked whether the U.S. would intervene to assist two Canadians detained in China after the arrest, in Canada, of a Huawei CFO Meng Wanzhou on U.S. charges, Trump said he would do "anything" to help the the Canadians.

He went on to specify that, if asked by Trudeau, he would raise the detentions in a meeting with Chinese President Xi Jinping next week.

The meeting was a striking change of tone.

The last time Trump was in a room with Trudeau - at the Group of Seven meeting a year ago in Quebec - the day ended with the U.S. leader lambasting the prime minister from his airplane with a series of not-so-neighborly tweets.

The challenge now will be to keep Thursday's exchanges friendly and on-script - that is, to avoid any unexpected tweets throughout the day.

It may help that the meetings will focus on two interlocking issues - trade and China - that are front of mind for both Trump and Trudeau.

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 agreement.

But before Trudeau pushes to get it through parliament this summer, he wants to know where the process stands stateside.

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 Lighthizer told a senate hearing on 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."

Trudeau is coming to check in on this assessment.

Pelosi will be key. Democrats have raised questions about several parts of USMCA, 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 they have to have in-depth conversations with Lighthizer on this."

Locke said he was hopeful the sides could cut a deal.

"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."

The big question, for now, is what Pelosi has planned.

"Trudeau will be trying to get a sense of what Nancy Pelosi really wants," said Eric Miller, a U.S.-Canada trade specialist who runs the Washington-based Rideau Potomac Strategy Group. "Pelosi will call the shots on what will happen on USMCA in the short and medium term."

Canada has said it does not intend to reopen negotiations. Trudeau's goal is to persuade Pelosi that if his Liberal government is happy with the trade and labor provisions, she can be, too.

Though trade will be the focus, Trudeau and Trump will also talk China, the Canadian side said.

The arrest in Vancouver of Huawei executive Meng Wanzhou on U.S. charges has put Canada in a tough spot with Beijing.

After Meng's arrest, Chinese authorities detained two Canadians in China in what is widely seen as retaliation. They have been languishing in detention centers ever since.

China already has taken aim at Canada's economy, blocking some agricultural imports. They warn of more to come if Meng isn't released.

Canadian officials have been frustrated by what they see as a lack of strong U.S. support. They want the Trump administration to do more.

Many expect Trudeau to ask Trump to raise Canada when he meets with China's Xi Jinping at the Group of 20 meeting next week in Japan.

Dawson, of the Wilson Center, said Canada's best bet could be an 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."

First step: get back to being buddies once again.

This article was written by Emily Rauhala, a reporter for The Washington Post.