WASHINGTON (AP) — Congressional lawmakers will seek to levy sanctions on all Iranian banks, part of a sweeping effort to push the Obama administration to squeeze the Islamic republic’s economy further and force Tehran to abandon its nuclear program.

A congressional aide said Tuesday that lawmakers in the House of Representatives and the Senate soon would introduce bipartisan legislation compelling the Obama administration to expand US sanctions to every Iranian bank. More than 20 Iranian banks, including the powerful Central Bank and all of Iran’s largest state-owned banks, currently are subject to sanctions under Treasury Department rules. But several other Iranian institutions still are able to do business around the world.

The legislation also would sanction government-owned foreign financial institutions, including foreign central banks, engaged in non-oil transactions with Iran, the aide said. Under current US law, those institutions will be sanctioned only for oil purchases beginning in late June.

The pending legislation aims to tighten loopholes in current US laws. The legislation is being pushed by Democratic Rep. Brad Sherman, and staff in Sen. Mark Kirk’s office, who are working on the measure while the Illinois Republican recovers from a stroke.

A second person briefed on the matter confirmed the legislative plans. Both sources spoke on condition of anonymity because they were not authorized to speak publicly.

Lawmakers were pushing forward with the tougher sanctions even after Israeli Prime Minister Benjamin Netanyahu said in meetings with members in Congress this week that sanctions were not an effective strategy for dealing with Iran.

The Obama administration is trying urgently to persuade Israel not to launch a military attack on Iranian nuclear targets, and instead give sanctions and other economic pressures time to take hold. At a White House news conference Tuesday, Obama defended the utility of economic pressure, saying “Iran is feeling the bite of these sanctions in a substantial way.”

US officials acknowledge privately that they cannot be sure the economic pressure will lead Iran to abandon its nuclear ambitions.

Congressional lawmakers have been pushing forward in recent months on increasingly stringent sanctions, in some cases seeking even tougher penalties than those preferred by the Obama administration.

The Senate Banking Committee approved tough new penalties in January that would target Iran’s Revolutionary Guard Corps, require companies that trade on the US stock exchange to disclose any Iran-related business to the US Securities and Exchange Commission and expand penalties for energy and uranium mining joint ventures with Tehran.

The bill also would deny visas and freeze assets on individuals and companies that supply Iran with technology that could be used to crack down on its citizens, such as tear gas, rubber bullets and surveillance equipment.

Iran insists it does not seek to build a bomb, and is developing its nuclear program for peaceful purposes.

Copyright 2012 The Associated Press.