Justin Trudeau's meeting with Donald Trump in Washington on Thursday is set to be a deal-making session that could turn on an exchange of favours on North American trade and the plight of two imprisoned Canadians in China.

The transactional diplomacy could provide the prime minister with the elusive common ground he has constantly sought with the volatile American president.

Trudeau's one-day whirlwind visit to the U.S. capital might also repair the two leaders' personal relationship, which fractured when Trump insulted Trudeau on Twitter a little more than year ago after departing a G7 summit in Quebec.

Trudeau's Oval Office meeting on Thursday is ostensibly about providing momentum to efforts in both countries to ratify the new North American trade deal.

In Mexico, the ratification process is well underway. According to the Mexican Embassy in Ottawa, that country's Senate voted 114 to 5 for the new agreement on Wednesday. And as long as Trudeau has a Liberal majority in Canada's House of Commons, he can push a ratification bill through the necessary votes fairly swiftly.

But in the United States, Trump's success hinges on persuading his Democratic opponents in the House of Representatives, the lower house of Congress, to allow the actual start of the ratification of the United States-Mexico-Canada Agreement (USMCA). That's where Trudeau could prove handy to Trump.

Trudeau is also to meet House of Representatives Speaker Nancy Pelosi, Trump's most powerful Democratic opponent, during his Thursday visit to Washington, says the Prime Minister's Office. In addition to Pelosi, he will meet the Republican leader in the upper chamber of Congress, Sen. Mitch McConnell.

Trudeau is waiting for the trade deal to move through the U.S. Congress before putting Canada's ratification to a vote in the House of Commons. "We are going to make sure we are keeping in step with them, we have an ability to recall Parliament if we need to," he said Wednesday in Ottawa before leaving for Washington.

Analysts say the sight of an enthusiastic Trudeau expressing support for the new deal alongside Trump in the Oval Office could serve as a persuasive example especially to House Democrats. As much as Pelosi would like to deny Trump a trade victory, she and her party have concerns about the deal's substance as well. They want stronger provisions to enforce new labour standards in Mexico that would raise wages and give unions more power.

In return, Trudeau will be counting on something from Trump — vocal support for the plights of Michael Kovrig and Michael Spavor, the two Canadians detained in China for the past six months after Canada arrested a Chinese high-tech executive on an American extradition warrant. Their cases are widely viewed as retaliation for the arrest of Meng Wanzhou, who the U.S. wants to stand trial for fraud for allegedly using U.S. banks to circumvent sanctions on Iran.

The support Trudeau seeks likely includes Trump's going to bat for the Canadians in his face-to-face meeting with China's President Xi Jinping at next week's G20 leaders' summit in Japan. Vice-President Mike Pence pledged that Trump would do just that on his visit to Ottawa last month, but Trudeau will find out Thursday whether the mercurial president currently plans to follow through.

"Trudeau has to remind the White House, remind President Trump, how Canada has been a solid supporter and player on USMCA ... Canada is supporting the president's initiative and in exchange Canada could really use some support on the China issue," said Laura Dawson, the director of the Canada Institute of Washington's Wilson Centre.

Canada can't do anything on its own with China, said Dawson, and now needs U.S. help. That could include withdrawing the extradition request for Meng, speaking to Xi on Canada's behalf, or preferably both.

"It wouldn't be completely out of character with what we know about the president. The president is a very transactional guy. Personal relationships, doing a favour for somebody, helping a buddy out is exactly in line with his modus operandi," said Dawson.

Eric Miller, president of Rideau Potomac Strategy Group in Washington, said Trudeau needs to use the visit to gauge how much he can count on Trump.

"Where is the U.S. as an ally to Canada when it comes to China? Is it: 'Dude, you're on your own'?"

On the trade front, Canada has been building strong support for the new NAFTA and open borders within the U.S. and it has many American business allies who remain active.

Similar to Canada's full-court press of cabinet ministers, provincial premiers and business groups, the Canadian American Business Council is leading its own charm offensive targeting U.S. lawmakers.

"We're trying to cause enough conversations so they don't come out against it prematurely and are open to hearing the economic arguments," said Scotty Greenwood, the chief executive of the Washington-based group and a U.S. diplomat in Ottawa when Bill Clinton was president.

"You see the Democrats keeping their powder dry, which is what we want."

Trump's trade czar Robert Lighthizer told the House of Representatives' powerful ways and means committee on Wednesday that he's willing to co-operate with Democrats to move forward on the new trade bill.

"The bill has been public and we have been in negotiations for nine months," he said his second appearance on Capitol Hill in as many days. He praised Pelosi for her efforts, as he did Tuesday before the Senate finance committee, but he's clearly in a hurry to ratify the new trade pact.

"Getting this done sooner rather than later is in everybody's interest. It saves jobs, it helps the economy, it gets certainty in place."

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