Phyllis Caldwell, head of Treasury's Homeownership Preservation Office, said the most recent data released at the end of January showed that the program "is doing the job it was designed to do" and remains "on pace to meet" the goal of helping 3 to 4 million homeowners by the end of 2012.
A key stumbling block for the program has been getting mortgage servicers to increase the rate of conversions from trial modifications to permanent ones.
As of the end of last month Bank of America had only finalized 12,761 permanent modifications out of a total of more than one million eligible borrowers. Wachovia Mortgage has made 330 permanent modifications out of 86,461 eligible homeowners.
The administration late last year launched a mortgage conversion drive to increase the performance of servicers.
Criticism of the housing plan has not only come from Republicans, but from Democrats, too.
At a December hearing in Washington, lawmakers on the House Financial Services committee blasted the program.
"We're very unhappy," said Rep. Maxine Waters, D-Calif.. "Our constituents are in pain. Our communities are at great risk. Treasury, you're just too slow. You talk about all the things that you're going to do, how you're going to improve. We've been listening too long."
The panel's chairman, Rep. Barney Frank, D-Mass., said he felt "a great frustration" with the government's efforts to stem the foreclosure crisis.
"No one should think we are doing a satisfactory job," he said.
Rep. Emanuel Cleaver, D-Missouri, urged Treasury to crack down on under-performing mortgage companies.
"We haven't spanked anybody so I think they've come to the conclusion that spankings are not on the agenda," Cleaver said.