Treasury Undersecretary Beryl Sprinkel said today that the United States wants to add to the lending resources of the World Bank and the International Monetary Fund, provided they continue to demand strict conditions from borrowers.

He said at a press conference during the joint annual meetings here of the two lending institutions that the problems of large multinational banks, including U.S. banks that are overexposed in Mexico, arose because neither they nor international agencies had been strict enough in the past.

"We don't believe you can solve problems by throwing money at them, and we've said so from the beginning," Sprinkel said. He added that, as the United States tries to help the IMF devise a rescue operation for Mexico, "It's not our job to make sure that no bank loses capital.

"Some of them do have bum loans. Some of them may be rescheduled, and some of them may never be collected."

Sprinkel reiterated that the United States opposes a "substantial increase" in IMF quotas -- the deposits of currency made by IMF member nations for lending to the poorer members -- because "there is a risk that a large quota increase will result in less conditionality."

Nonetheless, Sprinkel claimed there had been some "movement" in the U.S. position, which originally had been that there should be no quota increase at all. He said that "we stand ready to assure that substantial funds will be available to the IMF and the World Bank."

His remarks appeared designed to rebut the frequently voiced comment in the convention hall and privately in hotel corridors here that the United States was "dragging its heels" and in effect preventing a large increase in resources that almost everybody else argues is essential in the present crisis.

But he acknowledged at the same time that "there is no relaxation in our effort to have the IMF maintain a strict lending policy. We do not want to throw good money after bad."

Meanwhile, World Bank officials tonight announced the terms of a new agreement by which all of the 32 nations except the United States that are donors to the bank's soft-loan agency, the International Development Association, will contribute about $2 billion for fiscal year 1984 to keep the concessional monies flowing to poor nations.

Moeen A. Qureshi, senior vice president of the bank, said that, under what will come to be known as the Toronto Agreement, these nations will advance enough money to keep the IDA operating at about the same level as during fiscal 1983, that is, about $3.5 billion. However, many of the 31 nations are insisting that their contributions to the 1984 period be separated into a "special fund," parallel to the regular IDA account. The money from this special fund will be "tied" for procurement purposes in the donating countries, or in the recipient countries.

Qureshi said that as of tonight, six nations had specified that their 1984 contributions will be in the special fund, 11 will put their monies in the normal IDA account and 14 have not yet decided which account to use.

On domestic U.S. economic issues, Sprinkel gave an upbeat view, saying that "the low point in the recession may have been reached." He said that significantly better prospects for U.S. economic recovery were one element of a somewhat brighter world economic picture that American delegates have been painting in their reports to other nations here.

"We have tried to offer some balance to the pessimism," Sprinkel said. As positive elements in the world outlook, he cited not only the improving U.S. picture, but lower inflation rates in European industrial nations, the decline in the Organization of Petroleum Exporting Countries surplus, and lower oil prices. He conceded that the American economic recovery would not be rapid, but added that too fast an upswing would not be desirable.

"We have expressed some understanding and sympathy for the plight of many nations and their citizens, while offering some confidence and hope for the future," Sprinkel said. "I think that is especially important for this meeting, which has been characterized by some of you as one of doom and spreading gloom."

Before leaving here for Washington on Monday, Treasury Secretary Donald T. Regan had said that the end result of U.S. banks' operations in Mexico might be that they would wind up with "a nick in their earnings." Sprinkel added that "a nick" did not mean that their capital would be eliminated.

In observing that some U.S. banks might wind up losing money in Mexico, Sprinkel said he was not trying to suggest that bankers never should take risks. In that case, he said, they would not be fulfilling their proper role. Rather, Sprinkel said, "this is not the time to encourage more risks" by backing a bailout procedure that failed to demand major reforms in the Mexican economy.

In dealing with the question of enlarged resources for both the IMF and the World Bank, Sprinkel insisted that the United States "had taken a leadership role" at this meeting by proposing a special "crisis fund" and by approving a "modest" increase in IMF quotas.

He expressed the hope that, by the time the Interim Committee of the IMF meets in Washington in April, there could be a deal approved incorporating both a modest increase in quotas and the idea for a "crisis" fund to supplement the quotas.

Asked to explain how the American crisis fund could be distinguished from monies the IMF normally borrows, such as the recent advance given it by Saudi Arabia, Sprinkel responded that, under the American plan, such monies would not have been loaned to India -- as part of the Saudi loan was dispersed -- because "in that case there was no threat to the international monetary system."