Twyford's wife, Joanna, will be undergoing treatment over the coming months.
The senior MP says negotiations are taking place in "the context of a Labour majority government."
Watch Ardern's speech here.
The donations were made to the Labour Party in 2017.
"Don't put on the brakes when now more than ever is the time that we need to speed up."
She said she was "very proud" of their efforts so far.
Her move comes after a legal battle over who was allowed to stand for the party's nomination.
"Keep talking," the Labour MP told him.
The Prime Minister has "one wish" for everyone.