ANNANDALE, Va. — President Barack Obama is promising that reconstituting the system of health care in this country will not add to the already heavy federal deficits.

Obama today told a community college audience in suburban Annandale, Va., that the cost of the program unquestionably is an obstacle to getting legislation passed.

But at the same time, the president said he had "made a commitment" to keep the changes "deficit-neutral," saying each change will have to be financed without bloating the deficit.

He acknowledged that "the hardest part is yet to come."

Obama said about two-thirds of the estimated costs of revamping the system will come from "reallocating" funds that currently are not being spent wisely.