WASHINGTON - President Obama plans to ask Congress for about $50 billion in additional emergency aid for states hit by Sandy, Democrats on Capitol Hill said Wednesday.

Housing Secretary Shaun Donovan told a Senate Appropriations subcommittee that the administration was still working on a request for a supplemental spending bill to provide the aid and expects to send it to Congress this week.

"We do not have a specific number," Donovan said.

The price tag is expected to be anywhere from $45 billion to $55 billion. Two Senate Democratic aides, speaking on condition of anonymity, put the number in the neighborhood of $50 billion.

"The president isn't going to leave New York, New Jersey, or the entire region to fight for itself," Donovan, who is coordinating the government's Sandy recovery efforts, told reporters.

Donovan urged Congress to take action in "the next few weeks" on the administration's forthcoming request.

Obama can request up to $5.4 billion more without hitting a spending ceiling. Several Republicans have said that more than that should be matched by cuts in other federal programs.

Donovan said that requiring spending cuts in other federal programs makes no sense. "We believe strongly that the country has to come together even in difficult times and stand behind places that have been devastated," he said.

He added that people were waiting desperately for help. He said it would be a mistake for Congress to quickly approve the $5.4 billion as a "down payment" and defer until next year providing additional funding.

"A down payment simply means that these families, these communities are going to be waiting for months or longer to get on with their lives," he said.

On Tuesday, the head of the Federal Emergency Management Agency, Craig Fugate, said the government's disaster relief fund still had $4.8 billion, enough to pay for recovery efforts into early spring.

New York, New Jersey, and Connecticut are together seeking about $83 billion in aid. Donovan described that figure as more of a damage estimate, saying some might be covered by private insurance and already-funded government programs.

Given the recent budget talks and pressure against spending, Congress is not expected to approve large amounts of additional money all at once.

The storm devastated coastal communities from North Carolina to Maine, killing more than 120 people. New York and New Jersey were hit the hardest.

Officials in the affected states expect the fight for more recovery money will last for months and probably require a series of spending bills. They also fear it will fade as a priority next year.

The four U.S. senators from New Jersey and New York said that $50 billion in new relief funds would not go far enough, if that is what Obama requests.

"While $50 billion is a significant amount of money, it unfortunately does not meet all of New York and New Jersey's substantial needs," said a joint release from Sens. Frank R. Lautenberg and Bob Mendendez of New Jersey, and Charles E. Schumer and Kirsten Gillibrand of New York. "While we know there will be additional supplementals, the Administration needs to come as close as possible to meeting our states' needs in the first request."

"I'm not sure where those reports are coming from," Donovan said in response to a question from Lautenberg. "We are still working on what our requests will be. We do not have a specific number."

Gov. Christie has already put in a damage estimate of $37 billion for New Jersey. He is planning to meet Thursday with officials from the White House and Congress.

Five members of New Jersey's congressional delegation declined to comment Wednesday, saying they wanted to wait for official word from the president.

A spokesman for Rep. Frank LoBiondo (R., N.J.) said that "the congressman hopes the president considers the devastation in New Jersey and other states and carefully reviews the thorough request Gov. Christie made for assistance. On specifics, we will wait to comment until we see an actual proposal from the White House."

Staff writer Jonathan Tamari contributed to this article.