Attorney General Griffin B. Bell, who last week announced he will allow emergency admission of 15,000 more Indochinese refugees into the United States, yesterday defended his action to congressmen who were miffed that they had not been consulted before the annoucement.

"That's cleary an ultimatum to us," complained Rep. Joshua Eilberg (D-Pa.), chairman of the House Subcommittee on Immigration, referring to Bell's decision to authorize entry for the refugees on Aug. 11.

"Everybody in Washington is so sensitive, they consider anything an ultimatum," responded Bell, who noted in his testimony before the subcommittee that he had contacted chairmen of appropriate committees before making the announcement.

Bell's authority to grant admission of refugees is part of the Immigration and Nationality Act, which has been strongly criticized by Eilberg and others. The act states that the attorney general should, but is not required to consult members of Congress before exercising his authority.

The act gives Bell authority to admit refugees only in "emergent, and individual situations" such as medical emergencies, and also in cases "deemed strictly in the public interest." Bell said that after considering the plight of the refugees, 7,000 of whom are stranded in the boats they used to flee Vietnam, he decided that the 15,000 refugees constitute such a case.

There are still an estimated 87,000 refugees in Southeast Asia, in boats offshore and in temporary camps.

Eilberg, whose subcommittee has approved a bill that would require the attorney general to consult Congress and would place limits on refugee admissions, accused Bell of "rubber-stamping" the administration's latest request for admission of refugees.

"I wouldn't be here testifying if I were rubber-stamping the request," the attorney general drawled.

He said, however, that he would never feel obligated to deny admission to refugees if congressmen he consulted disagreed with him.

During yesterday's hearing, officials from the State Department and the Department of Health, Education and Welfare discussed the future of federal expenditures to aid the 150,000 Indochinese living here now.

The Indochinese Migration and Refugee Assistance Act, under which $203 million has been spent since the fall of Saigon in April, 1975, will expire Sept. 30. If the administration and Congress do not approve further funding, the burden of assisting Indochinese refugees, 36 per cent of whom receive some aid will fall on state and local governments.

An HEW staffer said he understands "there will be an administration proposal for extension of funding with a phasedown of money for the programs."

The official said he believes the proposal will be made public "in a week or 10 days."

Congress, which must approve such a proposal, will be in recess until Sept. 7. This gives only three weeks for action on legislation before federal funding is cut off.

"I think we can do it - we did it in two weeks after Saigon fell, when the original legislation was approved," said Rep. Hamilton Fish Jr. (R-N.Y.).