Sen. Mark WarnerMark Robert WarnerNSA spying program overcomes key Senate hurdle Dem lawmaker wants briefing on major chip vulnerabilities Week ahead: Tech giants to testify on extremist content MORE (D-Va.) signaled Monday that he may be reluctant to back a public option in healthcare reform legislation, but left the door open to other government plans that have been floated.

Warner, a centrist Democrat, laid out criteria during an interview with a Roanoke television affiliate for a bill that he could support.

"I want to make sure there are some competitive alternatives to the insurance companies," he said. "But I'm concerned that simply expanding Medicare and Medicaid without getting the financial incentives right -- it's going to again end up driving up the deficit costs."

Warner has been coy about whether he would support a public option, and, along with other recalcitrant Democrats, could even end up scuttling Democratic leaders' fallback plan of passing healthcare reform with a simple majority vote using budgetary rules.

"I don't think a single payer, government-run system ought to be the goal of healthcare reform," he said, adding that he was not eager to support any bill containing new taxes to finance the system.

The first-term Virginia senator also saved some criticism for President Obama for not having adequately communicated the stakes in the healthcare debate.

"One of the things that I've been disappointed in the president's approach is that he didn't make the case to the American people that if we do nothing, we're still headed toward a disaster," he said.