Even though ratification of the controversial Trans-Pacific Partnership (TPP) has stalled in the US, President Barack Obama said he’s still “confident” the trade deal will earn the support of Congress.

"I remain confident we are going to get it done, and the reason I’m confident is because it is the right thing to do. It’s good for the country, it’s good for America, it’s good for the region, it’s good for the world," Obama said during a joint press conference with Vietnamese President Tran Dai Quang in Hanoi.

Leaders signed the 12-nation TPP, which includes the US and Vietnam as members, back in February, but it still requires ratification from each country’s lawmakers before it can go into effect. That process has stumbled, though, as public outcry against international trade deals increases. In the US in particular, all three major-party presidential candidates have come out against the deal.

TPP signing sparks dozens of protests across US over biggest trade pacthttps://t.co/IBh2dM0mYnpic.twitter.com/EheASLmkSH — RT America (@RT_America) February 5, 2016

In Vietnam, Obama reiterated why he believes the TPP is so important, noting that the Asia-Pacific region is the fastest growing part of the world and represents a huge market for the US. He said the TPP would eliminate some 18,000 tariffs that have been placed on American goods sold in Asia.

"I have not yet seen a credible argument that once we get TPP in place we are going to be worse off,” he said. “We are demonstrably better off. American workers and American businesses are better off if we get this deal passed.”

However, opponents have railed against the TPP from the outset, criticizing the secret, years-long negotiations and arguing that it will primarily benefit large corporations, not workers. Protesters have argued that many of the regulations that would be stripped away would negatively affect laborers and the environment.

“It would make it easier to offshore American jobs, and it would push down their wages by putting them in direct competition with workers in Vietnam who don’t make but 65 cents an hour,” Lori Wallach, the director of Public Citizen’s Global Trade Watch, a non-profit consumer advocacy organization, told RT.

Even the economic impact could be negligible – or worse. According to a study from Tufts University earlier this year, the TPP would result in a reduction of 0.5 percent to US GDP over a decade. In Japan, another signatory to the deal, GDP was projected to shrink 0.12 percent. The study projected that gains for other countries would be small, ranging from 1 to 3 percent over 10 years.

Meanwhile, the US would lose almost 450,000 jobs, the study found. Other nations would also see job losses, and inequality could become exacerbated by the pact.

While the study was rather critical of the benefits of the TPP, economists have criticized it for “not accurately model[ing] effects of the trade agreement,” the Wall Street Journal reported. One study from Brandeis University found the US could see an economic gain of a modest 0.4 percent by 2030 with TPP in place.

Elsewhere, opponents have argued that the TPP would only exacerbate trends of other deals such as the North American Free Trade Agreement, which they blame for the current state of US manufacturing. Speaking with RT, Scott Paul, president of the Alliance for American Manufacturing, blamed trade deals for the loss of some 5 million manufacturing jobs since 2000.

In Hanoi, Obama defended several aspects that opponents of the deal have criticized, including that trade deals tend to open the US market to countries with lower wages, harsh labor practices and lax environmental regulations. The president said members of the TPP must make enforceable pledges to raise labor standards, recognize workers’ rights and address environmental problems.

The president’s continued defense of the TPP comes as he faces an uphill battle in Congress. Republicans who control the branch and are generally in favor of free trade deals have expressed skepticism, with GOP frontrunner Donald Trump claiming it would benefit China the most.

Obama also faces some intense opposition from Democratic lawmakers, as well as labor, environmental, privacy, and human rights groups. The frontrunner for the Democratic presidential nomination, Hillary Clinton, has come out against the TPP pending tougher regulations and renegotiation of certain parts. Her opponent, Vermont Senator Bernie Sanders, wants to kill the deal entirely.

If ratified, the TPP would cover roughly 40 percent of the globe’s economy and include the following nations: Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, the United States and Vietnam.