WASHINGTON -- The administration of U.S. President George W. Bush hopes to send a pact on civilian nuclear cooperation with Russia to the U.S. Congress in the next month, but a congressional aide said there would be strong resistance to the deal.

Concerns over Iran, which Washington accuses of trying to build an atomic bomb, could scuttle administration hopes that the deal would take effect by the time Bush leaves office in January.

The Bush administration says the nuclear deal with Russia could help solve the Iran problem by clearing the way for Washington to cooperate with Russia's offer to host an international uranium-enrichment center that would supply nuclear fuel to countries like Iran.

President Vladimir Putin says the proposed uranium-enrichment center, a sort of fuel bank, would discourage Iran and other countries from developing nuclear facilities that could be used for covert weapons programs.

"We can't isolate ourselves from Russia and then expect that these are the proposals that are going to be the solution to the Iranian nuclear program," a senior U.S. State Department official said, speaking on condition of anonymity.

"If there is an interest in the U.S. in investing in this consortium that Russia is establishing, getting U.S. industry involved in that whole international enrichment center, this [nuclear] agreement would be a useful baseline for that sort of cooperation," the official said.

A 123 agreement, so-called because it falls under section 123 of the U.S. Atomic Energy Act, is required before countries can cooperate on nuclear materials, such as storing spent fuel, or work together on advanced nuclear reactor programs.

At a summit last month in Sochi, Bush and Putin agreed to sign a nuclear cooperation deal "in the near future." The Bush administration is now going through the U.S. interagency process leading to the president's signature.

Bush would have to send the deal to Congress "in the next month or so" to give lawmakers time to consider it before they adjourn this year, the senior official said. "If we're to get it done, it will have to be soon," the official said.

Once the agreement is sent to lawmakers, it would go into force if Congress did not pass a disapproval resolution within 90 legislative days.

But the U.S. House of Representatives is already on record as saying the United States should shun civilian nuclear cooperation with Russia because of Moscow's aid in building Iran's plant at Bushehr and supplying it with fuel. A similar bill with some 70 co-sponsors is pending in the Senate.

If Bush signs the deal but does not submit it to lawmakers, that leaves it in limbo -- perhaps for the next president, who will take office in January, to send to Capitol Hill.

Some critics suspect the agreement is legacy-building by a White House in its last few months in office.

"A nuclear-cooperation agreement should be icing on a cake of trust and accomplishment with regard to nonproliferation. Instead, there's no cake," said Henry Sokolski, director of the Washington-based Nonproliferation Policy Education Center.