The volcanic alert level for Mt Ngauruhoe in the central North Island was escalated to level one by GNS Science today.
The famous volcano, often dubbed Mt Doom after featuring in Peter Jackson's Lord of the Rings film trilogy, received the new grading after GNS detected minor volcanic unrest.
The most likely hazards associated with the new level include steam eruptions, volcanic gases and earthquakes near the mountain.
Despite this, Mt Ngauruhoe was still in a normal, non-eruptive state, GNS said.