Opposition Leader Peter Dutton has flagged the Liberals’ support for possible budget cuts to help cover the cost of Australia’s security pact with the US and Britain.

Prime Minister Anthony Albanese unveiled the details of the agreement alongside his counterparts US President Joe Biden and British Prime Minister Rishi Sunak on a US battleship on San Diego harbour on Tuesday (AEDT).

The security pact includes a nuclear submarines deal that has a price tag of up to $368 billion.

On Monday night, Mr Dutton told ABC’s 7.30 he was willing to work with the government to make tough budgetary decisions to keep the AUKUS deal on track, such as measures to keep the National Disability and Insurance Scheme sustainable.

Asked if the opposition was prepared to support the Labor government’s budget savings to foot the AUKUS bill, Mr Dutton said the short answer was yes.

“In my budget in reply speech last October I said that we would work with the government if they had tough decisions to take, for example, keeping the NDIS sustainable,” he said.

“It’s an incredibly important program but it needs to be sustainable. And if the cost trajectory of that is going to result it in falling over, I think the government itself has pointed out that’s not sustainable.”

“If there are different ways in which we can provide support to the government, we’re happy to do that.”

Mr Dutton followed that up on Tuesday with a warning to the government about how it would find the money to fund AUKUS.

“There is an honest conversation that the government has to have. There’s no magic pudding,” he said.

“There’s no way in which you can sugar-coat it. There is extra money that needs to be spent in defence … That is incredibly important and you will require a lot of detail from the government in the run-up to the May budget, not just in the forward estimates but into the out years as well.”

He said the opposition would not allow the Albanese government to “cannibalise the defence force to pay for AUKUS”.

“I want to give this commitment to the Australian people today that come hell or high water, the Coalition will support AUKUS. We were the authors of it,” he said.

“We give full credit to the government for continuing it and arriving at today.”

Scott Morrison, who was PM when the AUKUS plans were announced, took to Instagram with his reaction on Tuesday.

“AUKUS is bigger than any one individual, party, government or partner nation. AUKUS has already altered the strategic calculus of the Indo-Pacific and will only continue to do so in the years ahead, supporting an enduring strategic balance in our region,” he wrote.

Under the deal confirmed on Tuesday, Canberra will acquire three US Virginia-class nuclear submarines as a stop-gap from approximately 2033 before a new SSN AUKUS-class hybrid vessel arrives in Australian waters a decade later.

The cost to taxpayers of the trilateral deal with the US and Britain will come in at an eye-watering $268-$368 billion over the coming three decades.

The plan ensures Australia will always have a baseline fleet of six submarines and have the option to buy an additional two Virginia-class submarines should there be any delays.

It will take $9 billion from the budget’s bottom line across the next four years and $50-58 billion within a decade.

Mr Dutton said the multibillion-dollar figure would span into the 2050s, but the most important numbers were the budgetary cost in the next three years.

“We would encourage the government to be transparent about the money that’s involved,” he said.

“Be upfront with the Australian people because it is a costly process but, as history has demonstrated, there’s an enormous price to inaction as well.”

Asked about the enormous cost of the program as he left India for the US at the weekend, Mr Albanese said he would explain to the Australian people why it was worthwhile given the deficit hole in the national budget.

“Yes, we will,” he said.

“Australia faces real challenges. We have said very clearly and explicitly that there are major pressures on expenditure, not just in defence, but in other areas as well.”

In the lead-up to the 2023/24 budget release in May, Mr Albanese reiterated the government needed to be prepared to “make some difficult decisions”.

– with AAP