Congressional budget wrangling in the United States, always tedious at best, is tying up money promised to the Manila-based Asian Development Bank and threatening the bank with some serious financial problems.

Sources at the bank say it has run out of money for soft loans to poor Asian countries, primarily because the United States has not yet approved the $445 million that the Carter administration promised.

Already three projects worth $22 million for Bangladesh, Laos and Sri Lanka have been held up. Another three scheduled projects worth $30 million in Western Samoa, Burma and Bangladesh are threatened.

Because of the uncertainty about the congressional allocations, the United States has not contributed the $171 million it promised to have provided by now. Bank officials say the problem is compounded by other donor countries, who are withholding their contributions to see what the United States does.

Most of the money is allocated to the special fund known as the Asian Development Fund. The U.S. pledge comprises 20 percent of the program. Developing countries can draw non-interest loans from the funds.

Last month the House of Representatives cut the pledged aid by half, but a conference committee restored the allocation.