Secretary of State Hillary Rodham Clinton insists the Obama administration is moving swiftly to impose tough new sanctions on Iran amid concerns in Congress that the White House will not be aggressive enough in cracking down on financial institutions that do business with Tehran’s Central Bank.

”What we are intending to do is to ratchet up these sanctions as hard and fast as we can, follow what’s going on inside Iran, which seems to be a lot of economic pressures that we think does have an impact on decision-making,” Clinton told the Senate Foreign Relations Committee on Tuesday.

The first round of penalties under the far-reaching defense bill that President Barack Obama signed into law on Dec. 31 goes into effect Wednesday, and lawmakers expected an announcement from the administration on the steps it plans to take to thwart Iran’s disputed nuclear program.

The United States, the European Union and others have slapped a rapid series of sanctions on Tehran; Congress added to the penalties late last year.

The law says that 60 days after enactment, the president must impose sanctions on any privately owned foreign financial institutions that knowingly conduct or facilitate any significant financial transaction with the Central Bank of Iran for any purpose other than the purchase of petroleum or petroleum products from Iran.

However, the Obama administration indicated it had no plans to mark Wednesday’s deadline by announcing a new swath of sanctions.

Instead, a top Treasury Department official said the administration was interpreting the law to mean that transactions with the Central Bank occurring after the deadline would put financial institutions at risk of penalties.

”Foreign private banks that, after today, engage in significant transactions with the CBI unrelated to the purchase of oil risk losing their correspondent account access to US financial institutions,” said David Cohen, Treasury’s undersecretary for terrorism and financial intelligence.

Clinton said the administration and Congress were on the same page regarding Iran and sanctions.

”The administration has been unequivocal about its policy toward Iran. With your good work and our efforts, we have passed the Menendez-Kirk sanctions. We are implementing those sanctions.

There has never been anything like them that the world has ever agreed upon,” she told the committee.

”We are diligently reaching out around the world to get agreements from countries for whom it’s quite difficult to comply with our sanctions. But they are doing the best they can. … We are focused on the toughest form of diplomacy and economic pressure to try to convince Iran to change course, and we have kept every option on the table.”

Sens. Bob Menendez, a Democrat, and Mark Kirk, a Republican, pushed for the sanctions in the defense bill, and in a rare unanimous vote, the Senate backed them 100-0.

During Clinton’s testimony, Menendez pressed her on the administration’s enforcement of the new sanctions. Menendez raised concerns about the criteria the administration was using to determine whether a country had achieved significant reductions in the purchase of petroleum.

The Energy Information Administration is scheduled to issue both a classified and unclassified report Wednesday on the availability and supply of non-Iranian-produced oil, reflecting the current production rate and the total reserve. The report will be the basis for whether the administration proceeds with the next round of sanctions.