The US House of Representatives ignored the objections of President George W. Bush and overwhelmingly approved a bill aiming to stop US funds going to the Hamas government in the Palestinian territories.
The measure, approved by 361 votes to 37 with nine abstentions, was passed hours before Bush was to host Israel's new prime minister, Ehud Olmert, at the White House for talks on the Middle East peace process.
The bill would bar direct assistance to the Palestinian Authority, but allows for limited exceptions, including health aid.
The Senate would have to pass its own measure and a bill would have to be signed by Bush before it became law.
White House press secretary Tony Snow indicated that the president Bush was opposed to the measure, however.
'We did not support that measure precisely because it does tie the president's hands in some of the activities ... which is providing humanitarian aid. We think it unnecessarily constrains,' Snow told reporters.
'This is an issue that we are pretty certain is going to come before a House-Senate conference, and we hope that those differences will be resolved there,' Snow said.
State Department spokesman Sean McCormack also expressed reservations about the House bill.
'Certainly, the president, as chief executive, needs to retain certain authorities to be able to fully exercise his responsibilities as the person who implements our foreign policy,' McCormack told reporters.
Supportive Republican lawmakers applauded the measure's passage however.
The vote would give Congress 'the opportunity to make clear that the US will not fund a government controlled by Islamist jihadists and enable it to carry out destruction against innocents in Israel or anywhere else,' Congresswoman Ileana Ros-Lehtinen, a Republican, said in a statement.
Democratic congressman Tom Lantos, the only Holocaust survivor to serve in Congress, issued strong support for the House bill.
'We in this Congress are sickened by the fact that the Palestinians chose Hamas as their leader,' Lantos said. 'We are sickened and appalled by everything that Hamas stands for.'
But some Democrats opposed the measure. 'The bill before us is one that the administration does not need nor want,' said Representative Earl Blumenauer (news, bio, voting record), a Democrat.
'It could potentially limit the US' ability to help our friend Israel if Israel decides in the future that working with a non-Hamas controlled PA (Palestinian Authority) is in their best interest,' Blumenauer said.
Washington has suspended aid to the Palestinian government since Hamas won an election. The US administration considers Hamas to be a 'terrorist' organization. It is refusing to back aid to Hamas unless it gives up its armed struggle against Israel, a key US ally.
The bill would also prohibits travel to the United States by Hamas members and provides for the United States to withhold contributions to the United Nations proportional to UN support for certain Palestinian-related entities.