Far North iwi Ngati Kahu is taking a stand against mining saying it will use reasonable force to remove any prospectors from its land.
It says neither the Crown nor any council has the authority to issue permits in its rohe (district).
Ngati Kahu says it's never been slow in standing up for itself and saying no.
Iwi chief executive Anahera Herbert-Graves says it's up to each hapu to decide how to deal with mineral companies.
She says that would include telling them to get off whenua and using reasonable force if necessary.
The Government says it's committed to unlocking any mineral resources to create a wealthier and more prosperous New Zealand.
The Crown says it's consulting with iwi about sensitive land - but Ngati Kahu says no-one from the Ministry of Economic Development has been in touch.
An aeromagnetic survey of Northland, to map out potential mineral deposits, is due to be made public sometime this month.