"When it comes to Social Security, Medicare and Medicaid, the American people told us to protect and strengthen these programs, not cut them," Harkin said.
"The American people want a change in the structure of who pays and making sure that we keep the programs that protect the poor, the disabled and the elderly," he told The Hill.
President Obama will meet Friday with lawmakers to open negotiations on how to avoid the "fiscal cliff," a combination of tax increases and automatic spending cuts that will hurt the U.S. economy unless lawmakers act.
In earlier talks, Obama backed roughly $100 billion in cuts to Medicaid, including a streamlined system for federal payments that would result in state governments shouldering more of the funding burden.
At Thursday's event, Sen. Bernie SandersBernie SandersSanders will 'absolutely' work with Trump to lower prescription drug costs Sanders says he will introduce 'Medicare for all' bill Sunday shows preview: Aftermath of failed healthcare bill MORE (I-Vt.) said he wanted to "send a very loud and very clear message to the leadership … in the White House" not to cut Social Security, Medicare or Medicaid.
Sanders added, "There are fair ways to reduce the $1 trillion federal deficit and $16 trillion national debt, but balancing the budget on the backs of the elderly, the sick, the children and the poor is not among them."
Republicans have said they won't accept new tax revenues unless Democrats agree to reform entitlements.
Tags Bernie Sanders