Ardern hinted at the announcement on a street corner meeting in Grey Lynn, where she was feted by supporters.
She also caught up with music legend and Grey Lynn local Chris Knox who suffered a massive stroke in 2009. The pair had a five-minute private conversation.
Prime Minister Bill English was campaigning in Tauranga with local MP Simon Bridges and Conservation Minister Maggie Barry.
She announced a promise of $69.2 million of new funding over four years as part of the target to make New Zealand predator-free by 205. Part of that is a $40 million contestable funds for predator-free community projects.
The biggest election play of the day was Act's new $1 billion policy to give schools the power to set teachers' pay rates and to give excellent teachers huge pay rises.
Schools which opted in would be bulk-funded by an extra $20,000 per teacher to do with what they wanted in terms of salaries, said Act leader David Seymour at the party's campaign launch in Epsom.
"Right now the best teacher earns the same as the worst teacher."
It has drawn immediately criticism from the teacher unions.
But Seymour says they are part of the problem and education had been monopolised by "thuggish union bullies."
He said the union had an all-for-one and one-for-all mentality which had "drained the joy from the teaching profession."
The unions collective agreements had suppressed wages for 30 years.
"You might end up paying a phys-ed teachers a bit less," Seymour said.
But inspirational teachers might be kept in the classroom at $120,000 year.
NZEI president Lynda Stuart said the Act position undermined education, teachers and unions.
It was good to see Act acknowledging teacher needed to be paid more, she said.
"But with teacher workload growing, along with a teacher shortage, all teachers need a pay rise, not just some."
