Jeffrey Zients, acting director of the Office of Management and Budget, testifies before the House Budget committee Wednesday. (Mattias Gugel/Medill)

WASHINGTON — Acting budget director Jeffrey Zients struggled to stay on script defending President Barack Obama’s budget proposal when he faced fire about its claimed savings from a Republican-controlled budget committee on Wednesday.

This was part of Zients’ two-day tour to testify before lawmakers about the newly released fiscal 2013 budget that projects $1.9 trillion in new taxes over ten years, a $901 billion deficit next year, and practically no reforms to entitlements such as Medicare and Social Security.

Republicans already have harshly criticized the spending plan, saying it does nothing to try to solve the long-term debt problems the nation faces.

The Obama administration says the budget foresees $4 trillion in savings over 10 years.

House Budget Committee Chairman Paul Ryan, R-Wis., argued that the large sum was a “gimmick” that claims savings that are already built into law, including $2 trillion from the Budget Control Act last September and $800 billion from getting out of the wars in Iraq and Afghanistan. He put actual savings at closer to $400 billion.

Rep. Chris Van Hollen, the panel’s top-ranking Democrat, said it doesn’t matter if the budget counts savings already provided by current law. Altogether, these laws and this budget show a sign of progress for the Democratic administration, the Maryland lawmaker said.

The message Zients and House Democrats shared during the hearing focused on a “balanced approach” to fixing the deficit, a commitment to investing in job growth, and promises Obama made to not raise taxes on Americans earning less than $250,000.

So, Zients was put in a tricky position when Rep. Scott Garrett, R-N.J., asked if the penalty that the health care law imposes on those who do not purchase health insurance was a tax.

The amicus brief the Obama administration filed before the Supreme Court supported the constitutionality of the mandate by calling it a tax.

“That Congress used the ‘penalty’ in the minimum coverage provision… rather than ‘tax,’ is immaterial to whether it was a proper exercise of Congress’s power over taxation,’’ the brief said.

In the end, Zients said the mandate was not a tax, making the point that Obama was committed to not increasing taxes on middle class Americans. His comments on the insurance mandate appeared to contradict the argument the White House is making in the courts.

Zients also declined to pinpoint a specific year when he thought the federal budget would be balanced, prompting Rep. John Campbell, R-Idaho, to say he does not think Obama cares about deficits and debt.

“This plan is Greece’s plan,” Campbell said.

Zients disagreed, citing the low interest rates on U.S. Treasury bonds as a key difference between the United States and Greece’s economies.

At the Senate Budget Committee on Tuesday, Zients was grilled on issues ranging from Medicare’s inefficiencies to what percentage of taxes the wealthy should have to pay as their “fair share.”

At that hearing, Sen. Jeff Sessions, R-Ala., asked Zients if the budget would actually increase federal spending rather than cutting it as Obama asserts. Zients would not directly answer, but said he was confident in the authenticity of the $4 trillion in promised cuts. Any discrepancies might be because of a “new budget baseline” the Office of Management and Budget used this year, he said.

“Mr. Zients, there is no spending reduction in this budget!” Sessions insisted.

After several Senate Republicans interrupted Zients’ comments to their yes-or-no questions, Budget Committee Chairman Kent Conrad, D-N.D., banged his gavel for order and defended Zients’ right to finish answering questions being fired at him. Sessions maintained the Republicans were not getting answers to their questions.

Throughout the House hearing Wednesday, Ryan and other Republicans said they appreciated that Zients came to Capitol Hill, but they were not envious of his tough job defending this budget.

“You were thrown into the breach,” Ryan said.