Asked if the Government had lost the battle against meth, Bennett said, "it's tough out there".
Last October outgoing Police Association president Greg O'Connor - now a Labour candidate - warned of a "second wave" of meth, and told his association's annual conference that in some parts of the country meth was cheaper than marijuana.
Shortly after being elected former Prime Minister John Key in 2009 launched a plan to drastically cut meth use.
Bennett denied Key's plan had failed, saying levels of meth use in New Zealand could be worse had it not been implemented.
"Most of what is being taken in this country now is coming from overseas and into New Zealand ...we are catching more, because we put more resource into Customs, we've got more dog patrols going on ... and we will not give up."
Labour's Corrections spokesman and Te Tai Tokerau MP Kelvin Davis said the meth problem was "absolutely" getting worse, and he saw the devastating effects in Northland.
"I was reading a report the other day that said someone who is using P would be able to get it within an hour if they wanted to," Davis said.
"I'm hearing that people don't even bother with weed anymore. If they go to a tinnie house it's only to get P. Weed is sort of obsolete these days."
Meth and other drugs were commonly smuggled into prisons. More resourcing was needed for rehabilitation programmes and other support, Davis said.