Overseas visitors could face new charges to visit national parks.
Associate Tourism Minister Paula Bennett says the work is underway to look at ways of extending charging of foreign visitors to national parks.
About 3.2 million visitors come from overseas a year and of those on holiday here about half go to national parks, the minister said at the Trenz travel event in Rotorua
"As those numbers grow you can see increased pressure," she said.
"We certainly aren't ruling anything in or out at the moment - it's something to discuss and not something that would be done lightly."
She said she was working with Conservation Minister Maggie Barry on the issue.
Foreign visitors did pay for using some tracks and huts, as do New Zealanders.
Bennett said charging for access was not on the cards.