Democratic presidential candidate Hillary Rodham Clinton leaves a campaign stop Wednesday at the Westfair Amphitheater in Council Bluffs, Iowa. (Nati Harnik/AP)

Democratic presidential candidate Hillary Rodham Clinton announced Wednesday that she opposes an expansive 12-nation ­Pacific Rim free trade accord finalized by the Obama administration this week, breaking sharply with the president over a deal she had championed while serving as secretary of state.

Clinton said in an interview with PBS during a campaign stop in Iowa that she would not support the Trans-Pacific Partnership (TPP) based on what she knows of the deal so far. The 30-chapter text of the agreement, which negotiators concluded Monday, has not been made public.

“As of today, I am not in favor of what I have learned about it,” Clinton said. “I have said from the very beginning that we had to have a trade agreement that would create good American jobs, raise wages and advance our national security. I still believe that’s the high bar we have to meet. I’ve been trying to learn as much as I can about the agreement, but I’m worried.”

Clinton’s opposition comes as she has sought to insulate herself against attacks from the left by rivals for the 2016 Democratic presidential nomination. Her stance aligns her with most of the Democratic Party, including Sen. Bernie Sanders (I-Vt.) and former Maryland governor Martin O’Malley (D), her closest competitors on the campaign trail.

But her stance is a significant blow to the White House because of her past support for the TPP deal as a cornerstone of the Obama administration’s efforts to deepen U.S. engagement in Asia to counter China’s rise. While serving as the nation’s top diplomat in Obama’s first term, Clinton hailed the accord as the “gold standard” of trade agreements during a speech in Australia in 2012.

Her reversal could complicate the path to final ratification in Congress for a trade pact that President Obama has called central to cementing his domestic economic agenda and foreign policy strategy in Asia. Republican leaders, who have been more supportive of Obama’s trade agenda, have also raised concerns this week about the final pact.

The White House launched a public relations blitz hours after the deal was completed, hoping to build support among lawmakers who are expected to vote on the pact early next year. Obama aides declined to comment on Clinton’s decision, but an administration official said Clinton had informed the White House of her intentions ahead of the interview.

Asked Tuesday whether the White House expected Clinton’s support, press secretary Josh Earnest said: “I would expect that she will take a look at the details of the agreement and arrive at her own conclusions. Certainly the administration would welcome her support, as well as the support of any other presidential candidates that wanted to come out in favor of the deal and urge Congress to support it. But ultimately, this will be a decision for her to make.”

In one possible sign of the White House’s concern, officials expedited the release Wednesday night of an administration analysis of the benefits for the TPP deal that was slated to be unveiled Thursday.

Administration officials said the accord would reduce or eliminate 18,000 tariffs on U.S. products, including beef, dairy, rice and automobiles, and they pledged that the deal includes new labor and environmental provisions that would raise standards in countries such as Vietnam and Malaysia, which are among the 12 nations in the pact.

The TPP seeks to knit together the economies of countries, including Japan, Canada, Mexico and Australia, that represent 40 percent of the world’s gross domestic product. The pact also would establish regulations for the flow of information on the Internet, establish a dispute-
settlement panel for multinational corporations, and protect patents and copyrights for pharmaceutical drugs, music and movies.

In the interview with PBS, Clinton cited a lack of protections in the TPP against nations that have manipulated their currency rates and provisions dealing with market protections for ­next-generation drugs developed by U.S. pharmaceutical companies.

“There are still a lot of unanswered questions,” she said.

Clinton’s break with Obama on trade is her latest attempt to distance herself from the president’s policies. She announced her opposition to the Keystone XL oil sands pipeline last month while the White House continues to deliberate. She renewed her criticism of Obama’s strategy in Syria after Russian troops established a military presence in that country. And she has advocated for using executive action to narrow loopholes on the sale of firearms at gun shows.

She hopes to consolidate support from the progressive wing of the party, including organized labor, which has blamed U.S. trade policies for contributing to a growing income gap. And Clinton’s position on trade is a bulwark against the possible candidacy of Vice President Biden, who would have trouble distancing himself from the trade pact because of his role helping Obama round up support for it.

Sanders, who blasted the pact this week as a win for Wall Street, said he was “delighted” that Clinton was also opposing the pact.

“I’ll let the American people determine who has credibility or not,” he told reporters after addressing the Congressional Hispanic Caucus Institute. “I’m glad that she reached that conclusion. That’s a conclusion I reached from Day One.”

Others were more gleeful in rushing to highlight what the Republican National Committee called a “flip flop.”

“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,” RNC Chairman Reince Priebus said.

“Wow, that’s a reversal,” O’Malley said of Clinton. “I was against the Trans-Pacific Partnership months and months ago.”

Clinton’s evolution on trade has been marked by sudden shifts in her position. Her husband, former president Bill Clinton, pushed the North Atlantic Free Trade Agreement (NAFTA) through Congress in 1993, and some labor unions have blamed that deal with Canada and Mexico for the loss of hundreds of thousands of U.S. manufacturing jobs.

During the 2008 campaign for the White House, both Clinton and Obama pledged to renegotiate NAFTA, hoping to win support in Ohio and other ­manufacturing-heavy states.

But once in office, they teamed up on a project to try to reduce U.S. foreign policy attention in Europe and the Middle East and shift it toward Asia, a ­fast-growing region where China had begun to expand its military and economic clout. Clinton announced the administration’s “pivot to Asia” in a Foreign Policy magazine cover essay in October 2011, a month before Obama traveled to the region to lay out his strategy.

“Our hope is that a TPP agreement with high standards can serve as a benchmark for future agreements — and grow to serve as a platform for broader regional interaction and eventually a free trade area of the Asia-Pacific,” Clinton wrote.

The Clinton State Department was so proud of the Asia rebalancing strategy that her aides fought for credit with the Obama White House, and some analysts had said that the policy has the potential to go down as her biggest accomplishment as secretary of state.

But Clinton signaled her hedge on the TPP in the spring when she did not offer support as Obama prodded Congress to back trade promotion authority legislation that would grant him “fast track” powers to smooth the path for trade deals, including the TPP.

In June, Clinton broke weeks of silence on the issue by telling the crowd at a campaign event that she sided with the House Democrats who had led a rebellion against Obama’s trade agenda. She called on Obama to listen to House Minority Leader Nancy Pelosi (D-Calif.) and the Democratic rank and file in Congress who wanted better protections for American workers. If he doesn’t, she said at the time, “there should be no deal.”

Obama ultimately won the fast-track authority with support from most of the Republican congressional caucus and only a small fraction of his own party. Just 28 of 188 House Democrats voted in favor of that legislation.

Defending the trade pact in an interview Tuesday with Marketplace, a public radio business show, Obama said, “If we don’t have strong labor standards, environmental standards, transparency, making sure that our companies are being treated fairly, if we don’t set them, then China will set them, and our businesses and our workers will be disadvantaged, so we put a lot of effort into this thing.”

Ed O’Keefe contributed to this report.