Prime Minister Justin Trudeau appealed to U.S. Democrats in Congress today to pass the new North American trade agreement, insisting the revised deal includes progressive provisions on issues like labour and the environment Democrats "care deeply about."

During a news conference in Ottawa after meeting with U.S. Vice-President Mike Pence, Trudeau said that while some Canadian Conservative politicians opposed such measures, his government saw them as "integral" to drafting a better deal.

"They are significant things that we look to the U.S. Democrats to understand are significant improvements and are issues that, like Canadian Liberals, they care deeply about," he said. "So we are confident that the work being done on ratification is possible because we made sure that, from multiple angles, this was a better deal for Americans, for Canadians and for Mexicans."

Democrats in Congress have expressed reservations about the deal — dubbed the U.S.-Mexico Canada Agreement (USMCA) by the Trump administration — saying it falls short on environmental protections, labour standards and the ability to enforce them in Mexico, the dispute resolution process and measures they fear could make drug prices more expensive.

Pence said he came to Ottawa to make the case again for speedy ratification of the new deal, which he said represented a "historic opportunity" to strengthen economic ties between the three countries.

"Issues in D.C. can arise, but the American people should know, people in Canada should know, that our administration is absolutely committed to driving forward, to seeing the Congress of the United States approve the USMCA this summer, and we're grateful for the prime minister's efforts seeing ratification here in Canada," he said.

But the Trump administration's approach to the trade deal may be getting tangled up with efforts to stem the flow of asylum seekers crossing the United States' southern border. This evening, The Washington Post reported that Trump is planning to announce Friday that he'll hit Mexico with new tariffs if it doesn't crack down on migrants entering the United States — a threat that could put the new NAFTA deal in peril.

Mexico's new ambassador to Canada, Juan J. Gomez Camacho, told CBC News today that his government is waiting to see if Trump follows through.

"Mexico has worked closely with U.S. authorities to manage the migratory flow coming from Central America, always considering the human rights of migrants," he said. "We will wait and see the content of tomorrow's announcement."

Late this afternoon, The Post also reported that the White House has plans to trigger a process that would allow Trump to submit the trade deal to Congress within 30 days, a direct challenge to Democrat House Speaker Nancy Pelosi.

The Post reported the Trump administration's decision to send a draft "Statement of Administrative Action" (SAA) to Congress risks heightening tensions with Democrats, who have said they need more time to scrutinize the deal and propose changes. A source tells CBC News Canadian officials were told by their American counterparts today that the SAA would be sent to Congress.

PM drove a 'hard bargain' in talks

Earlier today, Pence said that Trudeau stayed firm throughout tough negotiations to reach a new trilateral trade deal between Canada, the U.S. and Mexico.

"I want to assure the people of Canada that your prime minister drove a hard bargain, as did our president," he said before a closed-door meeting with Trudeau in his Parliament Hill office.

"But we believed it could be a win-win-win agreement and we think the USMCA, which will be the largest trade deal in the history of the U.S., will create jobs and opportunities in our country, it will support growth in Canada and Mexico and all across North America."

For Trudeau, who has taken heavy criticism from opposition MPs over how the negotiations were handled, Pence's expression of support was timely.

In the House of Commons Wednesday, Conservative Leader Andrew Scheer accused Trudeau of bowing to President Donald Trump's demands and letting the U.S. dominate the trade talks.

'Historic humiliation'

"President Trump is in command and, thanks to the prime minister, Canada is a mere onlooker," he said. "Why is the prime minister so proud of this historic humiliation?"

Scheer's spokesman Brock Harrison accused Trudeau of backing down on dairy, autos, pharmaceuticals and Buy American provisions.

"The vice-president's graciousness aside, the fact is Justin Trudeau backed down on almost every front on NAFTA. President Trump's own economic adviser said 'Canada gave very generously,'" he said in an email. "The deal speaks for itself."

Legislation to ratify the new NAFTA was tabled in the House of Commons Wednesday, but MPs are running out of time before the parliamentary session ends and the parties kick into pre-election mode.

Trudeau and Pence also discussed the crisis in Venezuela and the growing number of states adopting anti-abortion laws. Trudeau repeated his concerns about what he called the "anti-choice" movement, while Pence said he is proud to be part of a "pro-life" administration. Pence said they exchanged views on the topic respectfully.

Pence said the pair also spoke "extensively" about the two Canadians detained in China, and pledged that Trump would raise the issue when he meets with Chinese President Xi Jinping at the upcoming G20 meeting in Osaka, Japan.

U.S. 'standing with Canada' on detainees in China

"We are in the midst of significant discussion over our trading relationship, but I can assure you in that context going forward we're going to continue to urge China to release the Canadian citizens even while we deal with the larger economic and structural issues between the U.S. and China," Pence said.

"We are standing with Canada in this effort. We respect and are grateful for the strong stand for the rule of law that Canada has taken with regard to the Huawei executive and we'll continue to engage on the issue."

Michael Kovrig and Michael Spavor were both detained in China late last year. The men, who were arrested not long after Canada arrested Huawei executive Meng Wanzhou at the request of the U.S., were accused of national security offences.

They were formally arrested earlier this month and accused of spying.

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