Fifty-three people have so far died in Samoa after contracting measles, many of them young children. Nineteen children are in critical care in hospital and there are hundreds of new infections daily.
New Zealand nurses are on the ground helping with the mass vaccination programme along with NZ intensive care specialists.
"This is a tragic situation for Samoa, and New Zealand deeply feels for them," Foreign Affairs Minister Winston Peters told Checkpoint's Lisa Owen.
"We offered help weeks ago and waited for the response from the Samoan government.
"We didn't hear back until some time later, but the moment we did, we virtually had our medical teams ready to go."
New Zealand has provided more than 15,000 vaccinations and medical staff to help, he said.
He would not say if Samoa acted quickly enough on dealing with the measles outbreak.
"Our major concern from day one was to make New Zealand's systems available.
"We're also funding through Unicef 100,000 MMR vaccines to Samoa. So it's a huge effort that's going in from New Zealand's point of view."
The question of whether Samoa was warned earlier when Auckland had a measles outbreak was a health matter, "not for the Minister of Foreign Affairs".
"Should it be compulsory to be vaccinated in [New Zealand]? If you're asking my personal opinion, yes it should be compulsory. It saves lives massively.
"This conversation will go in because of both the events in New Zealand and Samoa."