Scotland's Finance Secretary John Swinney thinks it "highly unlikely" he would reverse the UK government's planned benefit cuts.
In a BBC webcast, the SNP MSP said the country needed to "live within the resources that are available to us".
Mr Swinney was speaking ahead of his party's conference in Aberdeen.
The Conservative government has plans to reduce the welfare cap, cut tax credits and change benefits linked to housing and disability.
During the interview, hosted by BBC political editor Brian Taylor, the minister was asked if he would reverse the proposals.
Mr Swinney said: "We must live within the resources that are available to us - we have had to wrestle with a reduction of expenditure in real terms of 10% since the 2010 general election."
He added: "Essentially this comes down to a question of affordability. I estimate that the cumulative loss of tax and benefit changes will be of the order of about £6bn.
"If you are saying to me, can I find £6bn within the expenditure available to the Scottish government to reverse all of those decisions, I think that it is highly unlikely."
Mr Swinney, who is Scotland's deputy first minister, explained that his government had found ways to mitigate some of the deficit reduction measures, including funding the cost of the so-called "bedroom tax" and freezing council tax.
He said: "We have been successfully in doing that and we will continue to do that."
It is not the first time Mr Swinney has talked about not being able to reverse the benefit changes.
He told the BBC's Sunday Politics Scotland programme that "not every single cut" could be reversed.
The politician was responding to comments, made on the same programme, by Secretary of State for Scotland, David Mundell, who said the Scottish government would be given the power to offset the Westminster changes.
During the BBC webcast Mr Swinney was asked if his government in an independent Scotland would reverse the Westminster cuts. In response he said it was important to run a "sustainable budget".
He added: "What we would aim to do is put in place a welfare system that was affordable based on what we inherited when Scotland became an independent country."
The interview was based on questions sent in by BBC news website readers.
The topics he tackled included income tax changes, a second independence referendum and bus passes for pensioners.