Feb 4: This post has been corrected.

Several American lawmakers have called for the United States to cut or suspend its foreign aid to Egypt. That aid, as we’ve noted, has been a decades-long symbol of the U.S. government’s support for Egyptian President Hosni Mubarak, whose years of repression are fueling these ongoing mass protests.

But can the U.S. government even cut aid?

Several reports have said that the aid is “tied to the Arab nation’s 1979 peace agreement with Israel,” or that the United States “promised aid to Egypt in return for maintaining the agreement.” Wikipedia describes the aid as being “part of the agreement.”

“That’s not the case,” a State Department spokeswoman told me. There’s no treaty that “obligates the U.S. to provide assistance to Egypt.”

According to a 2009 report from the Congressional Research Service, the peace treaty “ushered in the era” of continued U.S. financial support for Israel and Egypt. A letter from the United States to Egypt gave a basic outline for the aid and stipulated three years’ worth of military funding. But the letter—and the treaty—have few details about what an “expanded security relationship with Egypt” means in dollars, and it doesn’t commit to such funding in perpetuity. (Both Egypt and Israel got these letters—take a look.)

One thing the letter does say is that Congress has to approve the aid. The letter to Egypt, dated March 23, 1979, says that financing is “subject to such Congressional review and approvals as may be required.” Israel’s letter contains similar language.

“The problem is perception,” explained Scott Carpenter, a Keston Family fellow at the Washington Institute and former State Department official. “Egypt considers the aid a treaty commitment. The U.S. traditionally does as well, at least in the case of military assistance. Still, Congress can do whatever it pleases provided the President doesn’t veto its will.”

Once it has been approved, however, that funding is out of the direct control of Congress, Mother Jones reports. Funds that Congress has already approved but as yet remain unspent may be frozen by Obama administration.

Carpenter is member of the Working Group on Egypt, a nonpartisan group of Middle East and foreign-policy experts, which on Thursday released a statement calling on the U.S. government to “immediately freeze all military assistance to Egypt” if the government continues to employ violence against the pro-democracy protesters.

Sen. Patrick Leahy, a Vermont Democrat on the Appropriations Committee, has vowed to withhold aid until the unrest in Egypt ends. And while he’s joined by others who favor suspending aid to Egypt—including Texas Republican Rep. Ron Paul, a longtime critic of foreign aid—not all in Congress agree. The next chance lawmakers will have to act on appropriations to Egypt will be when it meets to decides how to fund the U.S. government for the rest of 2011.

The Obama administration has so far shown no signs that it plans to follow through on its warnings regarding aid. Though White House Press Secretary Robert Gibbs said last week that the administration would review its aid to Egypt, State Department spokesman PJ Crowley seemed to indicate in yesterday’s press briefing that no such review was occurring.

“We’ve said that we are prepared to review,” Crowley told a reporter who asked about aid to Egypt. “There’s no review ongoing at this time.”

Correction: This post previously referred to Rep. Ron Paul as “Sen. Ron Paul.”