Peters said staff were working "flat out" to ensure Best Start payments would be ready to roll out on time.
The PSA said Best Start would have to be processed manually by IRD staff, putting more stress on them.
Peters said the coalition Government had a lot of empathy for workers but reiterated the Government's line that wages could not all be fixed within one Budget.
Peters would not comment on ongoing mediation between nurses and DHBs in a bid to head off planned strikes in that sector.
"You tend to go to a bus stop where a bus might go by," he said when asked whether increased industrial action came with the change of Government.
"My hope is that there'll not be strikes."
Peters was asked about National leader Simon Bridges' now controversial Radio Hauraki interview.
He said he hadn't heard the interview.
Peters said he had also seen people get "funny ideas" when they go to university, alluding to Bridges' comments, but said they got snobbish and arrogant, in an apparent reference to Bridges.
Peters was asked about an upcoming business confidence survey this week.
He said the Government would work to gain the confidence of business.
"I will await the numbers."
Peters issued a warning to the owner of a Wairarapa property who had reportedly refused to allow access to walkers, as required under conditions set by the Overseas Investment Office.
He said those conditions would be enforced in future.
Peters said a change in the official cash rate was not on the radar of the Reserve Bank "any time soon".
Peters' Monday press briefing was later than usual following the tangi for the former Labour Cabinet minister.
Peters is filling in as Prime Minister while Jacinda Ardern is on parental leave.
Peters is Acting Prime Minister for the next six weeks. He held his first post-Cabinet press conference last Monday as Deputy Prime Minister while Ardern was awaiting the birth of her child.
