The Obama administration's vigorous effort to sell the recently negotiated Iran nuclear deal to the American public isn't going too well, according to a new CNN/ORC poll, which found that a majority of Americans want Congress to reject the accord.

Fifty-two percent of respondents said they want Congress to vote against the nuclear agreement between Iran, the U.S. and the five other P5+1 world powers, while 44 percent want Congress to approve the deal.

Among Republicans, 66 percent said the deal should be rejected, as did 55 percent of independents. Fifty-five percent of Democrats said Congress should approve the deal.

CNN found that 53 percent of younger adults between the ages of 18-34, who tend to vote more Democratic, approved of the deal, while among those age 35 and older, 56 percent said they reject it.

As shown by Vox, previous polls on the subject have found varying support for the deal among Americans. In a recent Washington Post/ABC poll, 56 percent of Americans said they supported the deal, while 52 percent didn't approve of how Obama has handled the situation with Iran. Pew Research Center found that 48 percent of Americans who knew about the deal disapproved of it, while 38 percent approved. And as HNGN previously reported, 53 percent of American Jews said they believe Congress should approve the deal, compared to 35 percent who were opposed, according to a recent L.A. Jewish Journal survey.

Under the deal, reached in mid-July by negotiators from the U.S., U.K., France, Russia, China and Germany, Iran has agreed to verifiably forego its nuclear weapon ambitions in exchange for significant sanctions relief.

Since then, the Obama administration has been aggressively pitching the deal to a skeptical American public and Congress. Many Republicans have vowed to do everything in their power to block the deal's full implementation.

Secretary of State John Kerry appeared before the House Foreign Affairs Committee on Tuesday, where he reassured lawmakers that "nothing in this deal is built on trust."

The deal ensures that Iran is "permanently banned" from developing nuclear weapons, Kerry said, adding that many of the restrictions imposed would be in place "not just for 15 or 20 years, but for the lifetime" of its nuclear program, reported The Associated Press.

Congress has been given 60 days to review the deal and either approve or reject it, or do nothing. President Obama has promised to veto any attempt by Congress to prevent its implementation.