Australia's Ambassador in Washington Joe Hockey has met Trump adviser Steve Bannon and chief of staff Reince Priebus at the White House amid ongoing discussions over the agreement to resettle refugees from Manus Island and Nauru.
The meeting came as Prime Minister Malcolm Turnbull claimed the deal would still be honoured by US President Donald Trump, who he described as "clearly a big personality".
The deal to take up to 1,250 refugees has become a flashpoint in diplomatic relations between Australia and the US, with Government sources confirming Mr Trump blasted Mr Turnbull during a weekend phone call.
The President reportedly described the deal as the "worst ever" while speaking with Mr Turnbull on Sunday morning, accusing the Prime Minister of wanting to export "the next Boston bombers".
A number of US senators called Mr Hockey overnight to offer apologies, including former presidential hopeful John McCain.
In a statement, Senator McCain described Australia's as "one of America's oldest friends and staunchest allies".
"We are united by ties of family and friendship, mutual interests and common values, and shared sacrifice in wartime," he said.
Today, Mr Turnbull acknowledged Mr Trump was clearly opposed to the deal, which the President branded "dumb" on Twitter.
"We secured the commitment from the US President that we wanted and that we sought, and we thank him for making that commitment," he told Sydney radio station 2SM.
"He's been very critical of the deal but we have persuaded him of sticking to it nonetheless."
The Prime Minister again dismissed reports that the President had hung up on the weekend call, which focused almost exclusively on the resettlement deal.
"If you are the Prime Minister of Australia you have to stand your ground — stand up for Australia and make your case — but with your good friends you make it privately," he said.
"I will leave others to comment on him, but clearly he is a very big personality."
When stopped outside his house on Friday morning, Mr Turnbull said White House press secretary Sean Spicer had described his conversation with Mr Trump as "cordial".
Mr Turnbull suggested the US President admired Australia's immigration policies, despite his opposition to the resettlement deal.
"He clearly believes in strong border protection policies and I think our policies, while they have been criticised in parts of the world, are now admired," he said.
Trump: 'I have a lot of respect for Australia'
Overnight Mr Trump slightly moderated his language, telling a Washington function that "I have a lot of respect for Australia, I love Australia as a country — but we have a problem".
He also urged people not to "worry" about the "tough" phone calls he was having with world leaders.
"A lot of countries are taking advantage of us. Terribly taking advantage of us," he said.