(CNN) - If the White House and Congress ultimately reach a deal on a budget, it won't look anything like Mitt Romney's plan, according to White House senior adviser Dan Pfeiffer.
"What this president will not do is come in - right after getting re-elected - and enact the Romney economic plan, which is what the Republicans in the House are proposing," Pfeiffer said Sunday on ABC's "This Week."
The president is expected on Wednesday to roll out his full budget proposal, some details of which were released Friday. According to senior administration officials, his budget will include proposed changes to Social Security and Medicare, key Republican demands, and tax increases, a key Republican sticking point.
House Speaker John Boehner said in a statement that "if the president believes these modest entitlement savings are needed to help shore up these programs, there is no reason they should be held hostage for more tax hikes. That's no way to lead and move the country forward."
The budget will include an offer Obama made to Boehner in December, officials said. That proposal included $400 billion in savings to Medicare over 10 years.
For Social Security, Obama plans to propose a key Republican request called "chained CPI," which is an inflation formula.
Proponents say chained CPI is a more accurate way to measure inflation than the current method, which they say overstates growth in consumer prices.
But some progressive Democrats oppose reductions to entitlements, and that opposition gives the president more room to say he's offering a compromise.
Both the House and Senate have passed budgets, but neither chamber's proposal is expected to go anywhere. The House version was drafted by Romney’s 2012 running mate, House Budget Committee Chairman Paul Ryan. It includes major reform to entitlement programs and no new taxes.
Pfeiffer said the president's focus "is to try to find a caucus of common sense" and people who are willing to meet in the middle but argued new taxes should still be part of the equation.
The president is scheduled to dine with Senate Republicans for the second time on Wednesday, the same day he releases his budget proposal. Asked Sunday whether Obama is getting any feedback from Republicans on the proposal, Pfeiffer said they've "had good conversations with them."
"The White House has been in contact with a lot of those folks, a lot of Senate Republicans we had dinner with, and so there is an opening there," Pfeiffer continued. "Is it going to be easy? Absolutely not. But there is a possibility, but this is going to require both sides to compromise."
– CNN's Ashley Killough and Jessica Yellin contributed to this report.