Despite her initial support for the Trans-Pacific Partnership (TPP), Hillary Clinton came out in opposition against the controversial trade deal on Wednesday.

The 2016 Democratic presidential front-runner voiced disapproval for the massive free-trade pact just two days after it was announced that the U.S. had struck a global trade deal with 11 Latin American and Asian countries.

Under the agreement, tariffs and import quotas would become cheaper and make trade between the 12 countries easier, while opening new Asia-Pacific markets to American businesses. Proponents also argue that the deal would expand trade and investment for the U.S., which would boost U.S. exports, small businesses and employment in America.

However, trade unions, environmental groups and opponents on the Left say it would send American jobs overseas and put U.S. workers in direct competition with low-paid workers in other countries. They also say the deal champions corporate interests and lobbyist groups.

During an interview with PBS NewsHour, Clinton backtracked on her support for the trade deal, which is set to become a key part of Obama's legacy.

"What I know about it, as of today, I am not in favor of what I have learned about it," Clinton told PBS' Judy Woodruff.

"I have said from the very beginning that we have to have a trade agreement that would create good American jobs, raise wages and advance our national security, and I still believe that is the high bar we have to meet," said Clinton. The former secretary of state added that she does not believe the TPP "is going to meet the high bar I have set."

Following her statement, AFL-CIO President Richard Trumka applauded Clinton for standing up against the agreement.

"America's working people are very pleased that Senator Clinton is opposed to the Trans-Pacific Partnership. I applaud her for taking this step and choosing to embrace workers' values. Her decision is a critical turning point, and will be invaluable in our effort to defeat TPP," he said in a statement sent to Latin Post.

Critics, however, say the 2016 hopeful is standing against the Pacific Rim trade deal in order to win over liberal Democrats. Back in 2012, she called the TPP the "gold standard" of trade agreements and praised it in her book "Hard Choices," reports Roll Call.

"Despite helping negotiate the Trans-Pacific trade deal as Secretary of State and calling it a 'gold standard,' Hillary Clinton reversed her position after admitting she hadn't even read the final agreement," said Republican National Committee Chairman Reince Priebus in a statement to Latin Post. "Hillary Clinton's painful waffling on TPP has been a case study in political expediency and is precisely why an overwhelming majority of Americans don't trust her."