WASHINGTON — Over three-quarters of US senators sent a letter Thursday to President Barack Obama expressing grave concern over the recent formation of the Palestinian Authority unity government supported by Hamas, which Washington considers a terrorist organization. Describing the unity government as representing “a serious setback to efforts to achieve peace,” the senators called on Obama to push PA President Mahmoud Abbas to cease the alliance with Hamas and return to the negotiating table with Israel.

According to the senators, Hamas’s role in the formation of the government has “undermined Congressional support for US assistance to the Palestinians.” That aid, they wrote, should only be provided when “we have confidence that this new government is in full compliance with restrictions contained in current law.”

The letter was initiated by Senators Ben Cardin (D-Md.) and Susan Collins (R-Me.), and was welcomed by the American Israel Public Affairs Committee, which congratulated Cardin and Collins on their leadership.

Since the announcement of a unity government earlier this month, the Obama administration – and the Palestinian Authority – has argued that the fact that the unity government is a technocratic regime with no Hamas members holding ministries means that a 2006 law that would deny funding to the PA over Hamas’s inclusion is not applicable.

In recent weeks, lawmakers have taken a number of directions in their interpretation of the Palestinian Anti-Terror Act of 2006. Those who support the immediate application of the act argue that Hamas’s support for the government — even if it does not hold any ministries – makes the law applicable.

The legislation, which was most recently reaffirmed as part of the Consolidated Appropriations Act for 2014, bars the United States from funding any governmental body “effectively controlled by Hamas, any power-sharing government of which Hamas is a member, or that results from an agreement with Hamas and over which Hamas exercises undue influence.”

On Wednesday, the administration continued to uphold that policy, confirming that in the face of a rocket attack against Israel launched from the Hamas-controlled Gaza Strip, it would not reconsider funding for the unity government.

During a press briefing held shortly after the attack, State Department spokeswoman Jen Psaki described it as “aggression against civilian targets and totally unacceptable.” She praised Abbas’s “prompt and outspoken condemnation of this attack” and said that the US expects “the Palestinian Authority will do everything in its power to prevent attacks into Gaza – from Gaza into Israel.”

While acknowledging “the reality that Hamas currently controls Gaza,” Psaki also noted that despite the unity government, “President Abbas’s ability to impact these type of attacks is really severely limited at this point in time.”

She added that the incident would not impact funding or relations with the interim government, “because the Palestinian people and our relationship with the Palestinian Authority is an important relationship to the United States.”

“We made a decision as the United States government that our assistance to the Palestinian Authority is important to the United States. And so that’s why it is continuing,” Psaki explained. “And they did – have met the criteria, including the Quartet principles that have been laid out.” Those principles include recognition of Israel, renouncing violence and adhering to previous agreements.

“We will be judging this government by its actions and we will address issues as needed moving forward, but nothing has changed at this point in time,” she said.