Leading members of Congress have warned Egypt of the loss of U.S. aid unless it ends support for Hamas.

Senior House and Senate members have determined that Egypt was supporting Hamas’ war against Israel in November 2012. They said Egypt could be encouraging Hamas and its Palestinian militia allies to maintain missile and rocket attacks on the Jewish state.

“Egypt — watch what you do and how you do it,” Sen. Lindsey Graham, a Republican from South Carolina, said. “You’re teetering with the Congress on having your aid cut off if you keep inciting violence between the Israelis and the Palestinians.”

Egypt represents the second largest beneficiary of U.S. assistance. For the last 30 years, Cairo has received $1.3 billion in military aid and at least $200 million in economic assistance.

Congressional criticism of Egypt’s alliance with Hamas has crossed party lines. A leading Senate Democrat said the new Islamist regime of Egyptian President Mohammed Morsi has yet to demonstrate its commitment to regional peace.

“The Egyptians have a real interest here in the agreement that they have with Israel,” Senate Armed Services Committee chairman Sen. Carl Levin said.

“But I think that they’re going to have to take some very serious steps diplomatically to make it clear to Hamas that they’re going to lose support in the Arab world if they continue these rocket attacks on Israel.”

Over the last year, the administration of President Barack Obma rebuffed several attempts by Congress to slash military aid to Cairo. Congress has passed legislation that Obama certify that Egypt remains committed to democracy and peace as well as security cooperation with Israel.

Officials said the administration has sought to engage Egypt in a strategic dialogue to restore cooperation. But they acknowledged that many in the Morsi regime feel no need to honor commitments both to Israel and the United States.

On Nov. 19, Obama again telephoned Morsi in what officials said marked another appeal for Egypt’s help to reach a Hamas ceasefire with Israel.

Later, Obama called Israeli Prime Minister Binyamin Netanyahu.

“Following the dinner tonight, President Obama called President Morsi of Egypt,” a White House statement said. “The two leaders discussed ways to de-escalate the situation in Gaza, and President Obama underscored the necessity of Hamas ending rocket fire into Israel.”