WASHINGTON - A clear majority of Americans support a nuclear deal with Iran that restricts Tehran's nuclear programme in exchange for loosening sanctions, according to a Washington Post/ABC News poll released on Thursday. Nearly 6 in 10 Americans, 59 per cent, would support a plan to lift international economic sanctions on Iran in exchange for new limits on its nuclear programme, the poll found.

Those terms match the language of a tentative framework for a deal agreed to by international negotiators on Thursday.

Thirty-one per cent are opposed to such a deal in the poll. 

Democrats are more willing to support such a deal, with 68 per cent in favour and 22 per cent opposed. Republicans are more closely divided, with 47 per cent in favour and 43 per cent opposed.  But the poll also finds that Americans remain deeply skeptical that an agreement would keep Iran from developing a nuclear weapon.

Thirty-seven per cent of Americans are somewhat or very confident a deal would prevent a nuclear-armed Iran, with 59 per cent having little or no confidence. 

The poll was administered hours before Tuesday's initial deadline to secure a framework deal.

The Obama administration, negotiators from five world powers and Iran are moving to finalise a deal before June 30. 

President Barack Obama praised the outlined plan Thursday as a "historic" agreement to curb Iran's ability to obtain a nuclear weapon, while many members of Congress and other world leaders expressed doubts over the plan.

Israeli Prime Minister Benjamin Netanyahu said that his country's Cabinet was "united" against the Iran deal, and Arab allies of the US have struck a cautious tone.

The framework deal would lift many international sanctions on Iran in exchange for scaling down its number of installed centrifuges and allowing for international inspections. 

The poll also indicates that a deal, which has become a second-term legacy issue for Obama, could play into the 2016 Presidential races.

A plurality of those surveyed, 49 per cent, state that the next President should favour a negotiated agreement with Iran, with 42 per cent opposing.

Here are other key findings in the poll:

1. US-Israeli relations 

Half of Americans disapprove of the way Obama is handling US-Israeli relations, compared to 38 per cent who approve, according to the poll.

That's driven mostly by Republicans, 86 per cent of whom disapprove, compared with 21 per cent of Democrats.

Meanwhile, 44 per cent oppose Israeli Prime Minister Benjamin Netanyahu's handling of the relationship, compared to 37 per cent who approve.

Tensions between the US and Israel appeared to escalate leading into this week's deadline for a deal. 

Top Obama officials skipped Israeli Prime Minister Benjamin Netanyahu's March 3 speech to Congress, held two weeks before Israeli elections, and the White House criticized Netanyahu over his pre-election remarks on a Palestinian State and Arab-Israeli voters. The poll found 39 per cent support recognizing a Palestinian state, while 36 percent are opposed.

2. ObamaCare 

Respondents in the poll were split on whether the next President should keep ObamaCare, the health law, with 49 per cent in favour of keeping it and 45 per cent in favour of a repeal. 

Democrats and Republicans polled were nearly flipped on their views, with 80 per cent of Democrats stating the law should be kept, while 82 per cent of Republicans saying it should be repealed. 

3. Immigration 

The poll found a majority of Americans, 51 per cent, support a pathway to citizenship, while 45 per cent are opposed to such a plan, which has been a top issue since Obama's executive action in November. 

As voters favoring a pathway to citizenship look to 2016, 55 per cent in the poll said it was "very" or "extremely" important to elect someone who shared their view. 

Forty-five per cent in the poll opposed a pathway to citizenship.

The poll of 1,003 adults was conducted March 26-29 via landlines and cellphones with a margin of error of 3.5 points.