U.S. President Barack Obama's efforts to reform health-care got a boost with the promise of support from Democrat Dennis Kucinich, who has been one of the bill's critics. (Pablo Martinez Monsivais/Associated Press)

U.S. President Barack Obama made a rare appearance Wednesday on Fox News, a network his administration has battled with publicly, in a last-ditch effort to get support for his health-care bill.

Previously, the White House had deemed the network a hardline right-wing branch of the Republican Party.

Obama appeared testy and irritated during the interview with Bret Baier, in which he tried repeatedly to defend his case for health-care reform.

Baier grilled him about the complex legislative process Democrats might use to pass the bill.

Obama told Baier point-blank to stop interrupting him. "Bret, you've got to let me finish my answers," he said.

"Sir, I know you don't like to filibuster, but," Baier said.

"Well, I'm trying to answer your question and you keep on interrupting," the president replied.

Baier wanted to know if the Democrats would use a procedure called "deem and pass," an obscure legislative move which would not require a formal vote on the bill.

"Whatever form that takes, there is going to be a vote for health-care reform," was the president's answer.

Republicans have called the "deem and pass" action sleazy and unfair. In the history of the U.S., the move has never been used in landmark legislation.

Obama may not need to use it, as he tries to win over critics within his own ranks about the bill.

On Wednesday, one of the bill's fiercest critics among the Democrats, Dennis Kucinich, said he would support the bill.