The enormous response to relief agencies assisting victims of the Indian Ocean tsunami has led at least one disaster organization to turn off the donation spigot.

Doctors Without Borders, which has distributed emergency aid to countries battered by the December 26 tsunami, is telling donors that it has received a “sufficient” amount of money for its South Asia relief efforts and is asking them to contribute to the agency’s general fund.

The organization, which has sent emergency medical teams to the hardest hit areas and has purchased and transported 200 metric tons of relief materials, has raised about $20 million for tsunami victims, according to a spokeswoman for Doctors Without Borders, Kris Torgeson.

“As you know, it is very important to MSF that we use your contribution as you intend it to be used,” states a message posted on the Web site of Doctors Without Borders, a medical relief agency founded in 1971 by a group of French doctors.

“This is why we want to let you know that at this time, MSF estimates that we have received sufficient funds for our currently foreseen emergency response in South Asia,” the statement says.

The decision by Doctors Without Borders to channel donations away from its tsunami relief fund reflects broader caution among relief agencies about honoring donor requests.

Agencies well remember the public anger directed at the American Red Cross in November 2001 when it announced that because it was receiving so many donations, it would set aside money intended for September 11 victims for other uses not directly related to the attacks. The agency quickly reversed course and pledged to use the “Liberty Fund” money for the victims.

“A lot of the groups are being much more cautious,” the editor of the Chronicle of Philanthropy, Stacy Palmer, said. She said she doesn’t expect donations to exceed emergency need to the extent they did after the September 11 attacks, “but it might be too much for the immediate relief effort.”

Many relief agencies, such as the American Red Cross, have not set specific fund-raising goals because they have not yet been able to complete their on-the-ground assessments of the emergency needs. In the coming weeks, much of the activity of relief agencies is expected to shift to a focus on longer-term aid, including money for rebuilding infrastructure.

Doctors Without Borders, which has sent 60 members of its international staff to tsunami disaster zones, decided to stop soliciting donations for its tsunami relief efforts to ensure that it would be able to properly spend the money.

“We feel it’s our responsibility to be transparent with our donors,” Ms. Torgeson said. She said the agency also wants to avoid the administrative costs of having to ask donors for permission to spend money for other emergency situations if it isn’t able to follow their instructions.

About half of the $20 million raised was restricted by donors to emergency tsunami relief efforts. For the remainder of the money, donors said the tsunami aid should be the first priority but allowed Doctors Without Borders to spend it on other disaster zones like Darfur, Sudan.

The Chronicle of Philanthropy estimates that major American relief agencies have raised $163 million since the tsunami struck – money that is supporting what is said to be the largest relief effort ever.

With the death toll still rising, private donations for emergency tsunami relief efforts are steadily accumulating.

The American Red Cross has raised $79.2 million – almost half of the private giving total – for the tsunami victims. Yesterday, it announced that the actress Sandra Bullock donated $1 million to the Red Cross International Response Fund for tsunami victims.

The American Red Cross says it isn’t actively soliciting money for its tsunami fund. A number of companies like Amazon.com have directed pledges to the fund. The American Red Cross has committed an initial $30 million for tsunami emergency relief efforts, $5 million of which has been spent on supplies, like hygiene kits and tents. The agency plans to spend another $25 million on food shipments as soon as it completes the “process of coordinating field logistics.”

The International Federation of Red Cross and Red Crescent Societies is scheduled to meet in Geneva today to discuss how the federation plans to use its resources.

“We are obviously very aware of the fact that if we feel that we have enough, we will come out and tell the American people that,” said Devorah Goldburg, a spokeswoman for the American Red Cross, which is one of 181 society members in the federation.

“There are definitely going to be longer-term things that need to be done,” she said. She said the American Red Cross has nine relief workers in the disaster area. CARE USA, another major relief agency, has declared a fund-raising goal of $25 million, a spokeswoman for the organization, Lurma Rackley, said. The group has raised $11.5 million.

Ms. Rackley said CARE is unlikely to call off donations for tsunami victims because “we are positioned a lot better than other agencies to absorb the donations.”

She said CARE has 1,500 workers in the tsunami disaster area and has had a constant presence in many of the countries for several decades. Almost all of its staff is made up of people who live in the countries.

As more tsunami victims are delivered emergency aid, CARE plans to spend donations on longer-term projects, like rebuilding schools, health centers, and community centers, purchasing fishing kits, and paying workers for clean-up projects.