The Obama administration on Monday plans to announce a campaign to pressure mortgage companies to reduce payments for many more troubled homeowners, as evidence mounts that a $75 billion taxpayer-financed effort aimed at stemming foreclosures is foundering.

“The banks are not doing a good enough job，” Michael S. Barr, Treasury’ s assistant secretary for financial institutions, said in an interview Friday. “Some of the firms ought to be embarrassed, and they will be. ”