President Obama on Thursday told Republican and Democratic lawmakers that they'll both have to compromise on tax increases and entitlement reforms if they're ever to reach as deal this year to reduce the nation's budget deficits.

It was the president's third trip to Capitol Hill in as many days, and he lunched with Senate Republicans before crossing the Capitol to meet with House Democrats.

The visits have been dubbed Obama's "charm offensive" as he tries to play a more hands-on role in negotiating with Congress over myriad budget issues after avoiding the Capitol for years.

Obama was in the building for nearly three hours Thursday, attempting to sell a "grand bargain" deal to both parties that would lower the cost of entitlements like Medicare and Social Security in exchange for new taxes.

"He was steadfast in saying we need to raise taxes," said Sen. Roger Wicker, R-Miss., after dining on lobster and pie with Obama. "He doesn't think anything is going to get done unless we could do that. That wasn't what we wanted to hear."

Obama didn't make many House Democrats happy either. He told lawmakers they would have to consider changes to Social Security, a program many of them want to spare from budget cuts.

"We Democrats have to be willing to entertain some [entitlement] reforms for the sake of stretching out the viability and life of the program," the president told House Democrats, according to Rep. Gerry Connolly, D-Va.

Obama said "the least painful" option is to change the way Social Security cost-of-living adjustments are calculated, which would slow the growth of spending.

Taxes and reducing the cost of entitlements are the two biggest sticking points for Republicans and Democrats.

More than 100 House Democrats recently wrote to Obama objecting to any proposal that would reduce Social Security benefits. And in the meeting Thursday, two Democrats -- Reps. Keith Ellison of Minnesota and Jerrold Nadler of New York -- stood up and challenged the president on his proposal to alter Social Security.

Obama offered Democrats assurances, according to Nadler, that he would not agree to entitlement reform unless Republicans were willing to raise "considerable revenue" through a tax increase, which the GOP has so far refused to do.

Entitlement reform "is a moot question," Obama said, "if the Republicans were adamant in their opposition to any tax revenues."

As far apart as the two parties appear, Obama seemed determined to reach a deal, lawmakers said. He told Republican senators that when they return from Easter break in April, he would set a specific timeline for reaching an agreement.

"There was an acknowledgment from the president that a timeline might help," Wicker said.

But the parties remain distrustful of each other.

Republicans believe Obama is setting them up for failure so he can use it against them in the 2014 elections. Democrats, meanwhile, are accusing Republicans of trying to force Obama to sell unpopular entitlement reform to the public, which could hurt Democrats politically.

Connolly said Republicans want Obama to "walk the plank, and we'll be right behind you."