Speaking of spending in general, he said, "We're making additional modest changes to get to balance."
Ryan had earlier floated the possibility of accelerating his Medicare proposal so it would apply to individuals currently older than 55.
Under pressure from some members of the rank and file, he decided against that — but drew criticism during the day from Democrats anyway.
"Every time they put in a budget, the first thing they do is ask seniors to sacrifice the most," said Rep. Steve Israel of New York, who heads the Democrats' campaign committee.
Ryan's Medicare plan would give future retirees a choice between enrolling in the existing program or a roster of private alternatives, although in any case they would receive a monthly check from the government to defray the cost and be responsible for the difference.
In its previous forms, the plan also capped the overall cost of the program.
Republicans say change is necessary in order to rescue Medicare from financial ruin as members of the post-World War II baby boom generation retire in large numbers. Democrats contend the plan would effectively end the guarantee of health care coverage that Medicare embodies by exposing seniors to prohibitively large cost increases.
Obama has proposed roughly $400 billion in savings over a decade from health care benefit programs, much of it from Medicare, but he has consistently rejected Ryan's approach.
Senate Democrats are drafting their own budget, expected to be made public next week. Officials have yet to say how large a deficit it envisions in a decade, but it will differ in significant ways from the Republican approach.
Sen. Patty Murray of Washington, the Budget Committee chairman, has said she will replace the across-the-board cuts with a blend of spending reductions and tax increase, an approach Obama favors.
Other Democrats say she will follow Obama's lead on Medicare, setting up a contrast with Republicans that her party hopes to exploit in the 2014 elections.
Obama's own budget has been delayed repeatedly this year, and it is not clear if he intends to release it before the House and Senate hold their debates this month.
If the administration waits until April, it could avoid certain embarrassment at the hands of Republicans. It is a ritual of budget politics for the party out of power in the White House to demand a vote on the president's budget, knowing it will fail, sometimes ignominiously.
Associated Press writers Andrew Taylor and Julie Pace contributed to this report.
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