"New Zealand now has a measles outbreak bigger than all of the US, is exporting cases abroad, and yet we still don't have enough vaccines to ensure everyone is protected," he said.
"The Government missed the early warning signs: three measles outbreaks in the first two months of this year and a warning from the World Health Organisation in April.
Associate Health Minister Julie Anne Genter said an 100,000 vaccines had arrived in the country, and were being checked for distribution early next week.
"More than double the amount of vaccines have been delivered this year, and we are on track for even more people to get immunised," she said.
The US figures include cases of measles that were brought back by Americans visiting overseas. US tourists to New Zealand numbered more than 300,000 last year.