Christopher Luxon's comments came after speculation about his leadership following a Taxpayers' Union Curia poll had National on 28.4% - down nearly 3 points from its poll last month.
Labour was up at 34.4%, while the Greens, ACT and Te Pati Māori were all up on 10.5%, 7.5%, and 3.2%, respectively.
New Zealand First had taken a slight drop to 9.7%.
Those results would give the centre-Left bloc 61 seats - enough to govern - while the coalition government bloc would fall short on 59 seats.
Luxon told Newstalk ZB on Friday he was "absolutely not" considering standing down, saying he had the skills to lead the National Party and the country.
"The only thing I am considering is the future of our children and grandchildren."
He said the only polling he took note of was National's own internal polling, which was processed in the United Kingdom.
"I would reassure you - if there was a problem, I would be doing something about it. But we are long way away from what we've seen published in a TPU poll today."
Luxon said he has "not thought about" what polling level would be the threshold for him to step down as Prime Minister.
"I have the full support of my team and my caucus."
The poll came at the end of a week where Luxon struggled to communicate clearly on the US-Iran conflict.
Speaking on NewstalkZB, he acknowledged failings with his personal communication.
"I've freely admitted, I'm not a career politician. I'm not always going to have the perfect most tidy soundbite like someone who's been there 20 years would do."
He believed the media had gotten carried away in its reaction to the public poll over the course of the day.
"The whole world seems to have got very exercised … the reason I'm going on your show is to clarify to people: no, I'm not doing that [considering my future]."
The general election will be held on November 7.
