Pressure is mounting on both sides of the Pacific for the confidential details of the refugee deal driving a wedge between Australia and the US to be exposed, for fear of what its unusual secrecy may be hiding.

Prime Minister Malcolm Turnbull negotiated the arrangement with the Obama administration but its future is unclear after President Trump suggested he may not honour it.

“I have a lot of respect for Australia, I love Australia as a country but we have a problem,” Mr Trump told US reporters on Friday.

Mr Trump did not rule out the deal, but he did blast it again, saying it was a ‘problem’. Photo: AAP

The President reportedly berated Mr Turnbull over the refugee agreement during a 25-minute phone call earlier in the week, saying it would be politically damaging to him.

Mr Trump, who regularly touts his tough immigration stance, is now facing calls within his own party to reveal the details of the resettlement arrangement, which is unpopular among hardline conservatives.

Influential US Republican Senator Chuck Grassley called on the White House on Friday to declassify the details of the deal.

“As I said before, the American people have a right to be fully aware of the actions of their government regarding foreign nationals who may be admitted to the United States,” Senator Grassley wrote in a letter to new Secretary of State Rex Tillerson.

“American taxpayers not only foot the bill for the majority of the refugee resettlement in the United States, but they bear any consequences regarding the security implications of those admitted to our country.”

Trump could back out

Experts in Australia have also warned that the secret nature of the deal, which is said to cover 1,250 refugees held in Nauru and Manus Island, could help Trump back out of it.

Many of the refugees are from Sri Lanka, Pakistan, Bangladesh, Iran and Iraq — nations targeted by Mr Trump’s new immigration ban on seven Muslim-majority countries.

Professor Alex Reilly, a migration law expert at the University of Adelaide, told The New Daily the fact the details were hidden could be problematic.

“It means that while Australia is relying on the deal to go ahead, it seems that the US has a lot of wriggle room to get out of it,” said Professor Reilly, who added that the secrecy also created uncertainty for the refugees.

“Without saying they’re changing their mind, the Trump administration can say, ‘We’ll honour it, but we’re going to vet people extremely strongly.’”

That could mean not accepting many of the refugees from the countries included in Mr Trump’s immigration ban, Professor Reilly said.

“If there’s no clear criteria for what that vetting is, it allows them to undermine the deal,” he said.

The men detained on Manus Island are worried the deal will fall through. Photo: AAP

“For example, if the vetting means deciding people who are from Iran or Iraq, for example, are too high of a security risk, well that’s effectively backing out of the deal.”

Dr Michael Clarke at ANU’s National Security College said it was uncommon for such a deal to be classified.

“I think the reports from Washington about Republicans being concerned about the classified nature are probably warranted here,” he told The New Daily.

“The issue is nobody seems to know the full scope of this deal.”

Two sides to the secrecy

It is also unclear what Australia has committed in order to secure the deal with Obama administration.

Dr Clarke said it was possible it could be related to the announcement by Mr Obama and the PM around the rotation of US marines through Darwin as a “quid pro quo”.

President Barack Obama signed the deal with Malcolm Turnbull. Photo: AAP

An agreement that saw Australia commit to accept refugees from Central American could also potentially be linked to the Manus and Nauru resettlement deal, Professor Reilly said.

James Curran from the US Studies Centre said Mr Trump may seek new commitments in return for honouring the resettlement agreement.

“It may take the form of a battalion in Iraq or freedom-of-navigation patrols in the South China Sea,” he said.

It would be extremely dangerous for Australia to be trading away key national security interests to shore up what in reality is a minor refugee deal, he said.

Dr Clarke also warned the White House’s conduct, including Mr Trump potentially reneging on the agreement, could raise concerns about the health of the US-Australia alliance.

“To seem him then renege and have details of the conservation leaked, I think that’s quite damaging to the relationship.”

“It says to long standing alliance partners that the guarantees, verbal or otherwise of the incoming relationship, can’t be trusted.”

– with AAP