Correction: A previous version of this story incorrectly stated that the Clinton Foundation had not previously described the disclosure restrictions on an affiliated Canadian charity. The story has been updated to reflect that an explanation had appeared previously in The New Yorker.

Democratic presidential candidate Hillary Rodham Clinton is facing questions about the relationships between her family’s foundation and its donors. (Jim Cole/AP)

With scrutiny of the Clinton Foundation’s financial practices threatening to create political problems for Hillary Rodham Clinton’s presidential campaign, the organization on Sunday took the unusual step of acknowledging “mistakes” but insisted that it is committed to transparency regarding its donors and operations around the world.

Nevertheless, the foundation explained that one of its affiliates — a Canada-based charity that bears Bill Clinton’s name — would continue to keep its donors secret because of restrictions in Canadian law.

The statement, in a blog post from the foundation’s acting chief executive, Maura Pally, followed the organization’s announcement last week that it was reviewing its federal tax filings because it did not properly report donations from foreign governments over several years starting in 2010. The foundation has come under criticism, including from some Democrats, for raising money from foreign governments while Hillary Clinton headed the State Department.

Sunday’s blog post also co­incided with national television appearances by conservative author Peter Schweizer, whose forthcoming book, “Clinton Cash,” charges that the State Department gave preferential treatment to foundation donors while Clinton was secretary of state and that the foundation violated its own promise to disclose all of its donors.

The Clinton campaign spent much of last week blasting the book as a partisan attack. Still, the statement Sunday was a sign that the growing focus on the $2 billion foundation and its relationship with donors may have begun to rattle Clinton’s team.

In an analysis of public records and Clinton Foundation data, The Washington Post found that there was an overlap of Bill and Hillary Clinton's charitable work and their growing personal wealth. The Post's Rosalind S. Helderman breaks it down. (Alice Li/The Washington Post)

“So yes, we made mistakes, as many organizations of our size do, but we are acting quickly to remedy them, and have taken steps to ensure they don’t happen in the future,” Pally said in the statement, which appeared under the headline “A Commitment to Honesty, Transparency, and Accountability.”

“We are committed to operating the Foundation responsibly and effectively to continue the life-changing work that this philanthropy is doing every day,” she wrote.

Pally described the mistaken IRS filings essentially as a clerical error. She said that overall revenue numbers provided to the IRS were accurate but that the foreign-government figures were mistakenly combined with other donations.

“While some have suggested that this indicates a failure to accurately report our total revenue, that is not the case,” she wrote.

Questions about the foundation in recent weeks, and surrounding the release of the new book, have prompted Republicans to charge that Hillary Clinton is too cozy with donors who have given millions to her family’s foundation.

On ABC’s “This Week” on Sunday, Schweizer said there had been a “troubling pattern” of assistance for foundation donors, though he acknowledged that he had no direct evidence of a quid pro quo. Clinton campaign spokesman Josh Schwerin said that concession revealed the book to be “nothing more than a tangled web of conspiracy theories backed by no actual evidence.”

At a Council on Foreign Relations event on women’s rights in New York City, Chelsea Clinton, vice chair of the Clinton Foundation, fielded questions about recent controversies over foreign donations to the foundation. (Council on Foreign Relations)
A Canadian partner

Pally also used the post to defend the foundation’s relationship with the Canadian-based Clinton Giustra Enterprise Partnership, which was founded in 2007 by Canadian mining magnate Frank Giustra to allow Canadians who donate to get a tax break in Canada. Giustra also sits on the Clinton Foundation’s board.

The partnership is funded largely by Giustra but also takes donations from other wealthy Canadians. It transfers much of its money each year — so far about $25 million — to the Clinton Foundation to support global ­anti-poverty efforts.

But it has received increased scrutiny in recent days, after a New York Times report last week examined the role of Giustra and another donor in a sequence of deals that led to a Russian state-owned company controlling large deposits of uranium around the world, including in the United States.

The deals with the Russians, because of national security implications, required approval by a committee of officials from U.S. government agencies, including the Clinton-led State Department. Clinton aides have said she did not personally intervene in the decision.

The Clinton Foundation has disclosed that Ian Telfer, the chairman of the uranium company sold to the Russians, donated no more than $250,000. But his financial support of the Clinton Foundation, at least indirectly, is probably higher. His Canada-based foundation has reported giving millions to the Clinton Giustra Enterprise Partnership.

In her Sunday blog post, Pally said the Canadian charity’s money goes entirely to a poverty initiative that also carries Giustra’s name, and it does not fund the general operating budget of the Clinton Foundation.

While the foundation has voluntarily disclosed information about its donors since 2008 as part of an agreement with the Obama administration prior to Clinton’s tenure at State, Pally said Canadian law does not permit the Giustra partnership to follow the same disclosure standards.

“This is hardly an effort on our part to avoid transparency — unlike in the U.S., under Canadian law; all charities are prohibited from disclosing individual donors without prior permission from each donor,” she wrote. The foundation’s explanation of the partnership’s disclosure restrictions first appeared in The New Yorker last week.

A spokesman for Giustra said Sunday that he has begun seeking written permission from major donors to disclose their names.

Giustra last week issued a statement promoting the work of the partnership, which he said has improved conditions around the world. Among other things, the partnership has funded cataract surgeries and meals for low-income children.

“Thousands of people, all over the world, have been helped by this initiative,” Giustra said. “I plan to continue that work long after the harsh glare of this week’s media stories has faded.”

Meanwhile, the Canadian tax benefits available for donors to the Clinton-Giustra partnership have since been extended to the broader Clinton Foundation. In 2010, the Canadian government approved an application to allow Canadians to earn tax breaks at home for donating to the U.S. charity. The Clinton Foundation is one of only three non-Canadian charities to hold the status. A spokeswoman for the Canadian agency that grants the status said the country’s laws prohibit explaining why the foundation was chosen.

“It’s an area that’s shrouded in secrecy,” said Mark Blumberg, a Toronto lawyer who specializes in Canadian charity law. “It invites criticism.”

Hillary’s role, political risks

The Clinton Foundation has a complicated structure, including 11 charitable initiatives, some of which have at times incorporated separately and filed their own tax returns to the IRS.

In 2013, after Hillary Clinton stepped down as secretary of state, she joined the foundation’s board, and the organization added her name, as well as her daughter’s, making the group’s full name the Bill, Hillary and Chelsea Clinton Foundation.

On announcing her presidential candidacy, Clinton stepped down from the board.

The political risk for her is that the foundation, once seen as a reputation-burnishing advantage, instead will become a permanent campaign liability.

Already, there are signs that the foundation’s potential conflicts are becoming rooted in the public imagination. In a routine at Saturday night’s White House correspondents’ dinner that was generally supportive of Clinton, comedian Cecily Strong cracked that relations with Israel will improve in the next administration.

“Just as soon as Israel makes a generous donation to the Clinton Foundation,” she joked.

Since Clinton announced her candidacy, the foundation has taken additional steps to ward off criticism. It has said it will now disclose donors four times a year, instead of annually. And it recently announced that while Clinton is running, it will accept donations from only a handful of foreign governments that have funded continuing programs.

The foundation had agreed to limit some foreign-government donations while Clinton was secretary of state and lifted those restrictions when she left government. However, it never banned donations from foreign governments, and the foundation has acknowledged accepting millions from governments in those years.

Last month the foundation announced that former health and human services secretary Donna Shalala, a longtime Clinton ally, would succeed Pally as the operational head of the charity. Bill Clinton remains on the foundation’s board, as does daughter Chelsea, who serves as vice chair.

In her statement, Pally said the foundation’s rules are intended to assist it in its mission of addressing climate change and childhood obesity and bringing low-cost drugs to people around the world.

“Without question the Foundation’s accomplishments stand on their own,” she wrote. “. . . One thing is clear, the Clinton Foundation has not been afraid to take on big challenges and see real results.”

Tom Hamburger contributed to this report.