He was responding to a letter from the International Union of Conservation for Nature (IUCN), which criticised the Government.
The union is the world's oldest and largest environmental network.
The director-general of the union, Julia Marton-Lefevre, and the chairman of the World Commission on Protected Areas, Nik Lopoukhine, say the Government risks damaging New Zealand's international reputation if it goes ahead with a proposal to remove protected parts of the conservation estate from schedule four of the Crown Minerals Act.
The criticism of the Government's policy is an almost unprecedented step by the apolitical organisation.
The union's letter would be considered by the Ministry of Economic Development along with other submissions made on the Government's proposal, Mr Brownlee said.
The areas proposed for removal from the protected schedule total about 7058ha (70sq km) and account for 0.2% of schedule four land (or 0.026% of New Zealand's total land area), an emailed response from Mr Brownlee said.
The minister has previously compared the amount of conservation land proposed for removal as similar in size to "a postcard on Eden Park".
Removal of the land from schedule four would not change its status as conservation land or as a national park or reserve, he said.
An even smaller proportion of this land area may be mined - as little as 500ha - subject to the strict environmental protections afforded to all conservation land.
The Government wants to add about 12,400ha to schedule four, he said.
Legislative "mechanisms" would ensure land and biodiversity values were protected, he said, in response to claims from the union the Government's stance risked New Zealand's "respected international reputation in biodiversity conservation".
Conservation is a major contributor to the economy in its own right, as well as providing New Zealand with a unique identity, Mr Brownlee said.
The Government wanted to establish a fund, using royalties from any mining activity on conservation land, which would be used to enhance conservation outcomes for New Zealand, he said.
