Arlene Foster has robustly rejected calls to resign over her handling of a botched green energy scheme.
The First Minister batted away allegations that she did not act appropriately when concerns were first raised about the controversial Renewable Heat Incentive (RHI).
Defending her position from China, where she is promoting Northern Ireland, Mrs Foster said she could not have acted differently.
"There really isn't anything more, with hindsight, that I could have done, given the advice that was given to me at the time," she added.
Mrs Foster was Economy Minister when many of the fatal errors in the scheme were made.
She has previously faced claims she did not do enough to pursue whistleblower allegations that sought to expose the flaws in the system.
Ulster Unionist leader Mike Nesbitt has gone so far as to call on Mrs Foster to consider her position, while other rivals have demanded she make a statement to the Assembly explaining why the whistleblower claims were not acted upon.
The DUP leader said the concerns were taken "very seriously" and referred to senior departmental officials.
"It has been acknowledged, indeed by the (Civil Service) permanent secretary, that I did all that was appropriate in the circumstances," Mrs Foster added.
"If anyone has any knowledge of the amount of instructions that a minister gives on a day-by-day basis, they would understand it is custom and practice actually, that it is only if there is some issue, if an exception is raised with me by an official, that it would come back to my desk.
"That didn't happen on this occasion. Of course I regret that it didn't happen on this occasion, but that's the reality."
The RHI aimed to cut the cost of green energy to encourage people off fossil fuels, but ended up landing ministers with a massive overspend as no cap was set on the number of claims.
That effectively enabled a business to burn unnecessary heat 24/7 just to make money. Overall, more than £1bn of public money will be paid by 2036 to Northern Ireland-based businesses that signed up to the scheme. Almost half of that will covered by the Executive.
Branding the programme a "squander made in Stormont", TUV leader Jim Allister asked Economy Minister Simon Hamilton: "It might cost him his job, but would the minister agree that at least one of his predecessors, particularly Mrs Foster, was asleep at the wheel in terms of failing to exercise supervision and ensuring that there were adequate cost controls in place?"
However, Mr Hamilton hit back and said previous ministers had been poorly advised by policy officials.