She also thought New Zealanders would be "perturbed" to see a government "singularly focused on the Opposition".
"Yes, their job is to hold us to account and I, of course, I wish any leader of the Opposition well in that job - it's an important part of our system - but I think the public wants us not to be focused on the bear pit and the fight of politics.
Ardern said she didn't get into politics "for the sport of it".
"I got into it because I believed it was a place that you could do good. It just so happens - between different parties - we just have different ideas of what that is.
"But in the meantime, my job is to keep us focused."
One issue Luxon has been critical of was Northland iwi's involvement in Covid border checkpoints.
Police and Tai Tokerau Border Control volunteers will be at checkpoints on State Highway 1 near Uretiti Beach in Waipū, and in Maungatūroto when the Auckland border restrictions change next week.
Labour's deputy leader and Te Tai Tokerau MP, Kelvin Davis said anger at these checkpoints was racist.
Mackay suggested Davis was "playing the race card" but the Prime Minister disagreed.
"I think, Jamie, the way you've characterised what's happening is - unfortunately, I'm going to call you out there - just wrong."
As long as a border control was led by the police, members of the local community could be involved, Ardern said.
Mackay asked if that meant dairy farmers in Waikato could stage one.
"We've always said they have to be led by the police. The police are the only ones who are able to legally stop people," Ardern said.
"Of course people have the legal right to move. All we're doing is checking that they're following the rules that the Government has set."
Listen below:
Most people would support a police-led checkpoint with backup from the defence force or Māori, Pacific, community wardens, Ardern said.
"Why wouldn't we use that extra support alongside the police?"
Finally, the Prime Minister said Covid-19 had made 2021 a tough year, especially with the Delta variant.
"I think we all knew the pandemic wasn't going to go away.
"But I think ... if we continue to just learn from everywhere and be willing to adjust, as we've done, that despite it being tough, we have come out in a better position than many other places.
"So my goal is to keep looking after people's wellbeing, their health, their economic wellbeing the best that we can under this tough environment - and I hope everyone gets a break."
Also in today's interview: Ardern defended the economy under her Government, said a processing rather than content issue prevented her from releasing briefing notes on Groundswell, addressed rumours about big property purchases, and discussed what the Omicron variant could mean for New Zealand.
