WASHINGTON (Reuters) - Democratic President Joe Biden got into a spirited exchange with congressional Republicans on Tuesday night, drawing boos by asserting that some hardline conservatives want to end Social Security and Medicare in exchange for raising the debt ceiling -- and then taking their cheers as a sign of "unanimity" not to do so.

"Some of my Republican friends want to take the economy hostage - I get it - unless I agree to their economic plans. All of you at home should know what those plans are," Biden said in his State of the Union address while appearing to try to engage Republicans in conversation.

"Instead of making the wealthy pay their fair share, some Republicans want Medicare and Social Security to sunset," the president said.

The Democratic president and Republican-controlled House of Representatives are locked in a standoff over raising the nation's $31.4 trillion debt limit, which Republicans say they will allow only in exchange for spending cuts.

Republican House Speaker Kevin McCarthy had previously said he would not consider cuts to the two programs, a position that members of his caucus loudly supported during Biden's speech.

Sitting behind Biden, McCarthy shook his head as Biden raised the issue.

"I'm not saying it's a majority of you," he added. "But it's being proposed by individuals."

Multiple House Republicans, including hardliners Marjorie Taylor Greene and Byron Donalds booed.

"We never said that!" Donalds said. Greene yelled "liar."

Biden even urged protesting Republicans to contact his office, saying he would "give you a copy of the proposal."

But between jeers from Republicans and cheers from Democrats for his proposal to tax the wealthy, the president finally managed to bring the entire room to standing applause.

"So, folks, as we all apparently agree, Social Security and Medicare is off the books now. Right?” Biden shouted. "All right. We've got unanimity!"

(Reporting by David Morgan and Gram Slattery; Editing by Scott Malone and Lincoln Feast.)