An adventure run on the slopes of Mt Ruapehu will be moved if the volcano does not erupt by this weekend.
Organisers of the Goat Adventure Run, a 21km trail from Whakapapa to Turoa Ski Fields, met Department of Conservation staff yesterday after Ruapehu's volcanic alert level was lifted last week.
DoC has warned climbers and trampers not to enter the summit hazard zone within 2km of the crater lake.
Run organiser Jason Cameron today said the run may still be able to go ahead on its designated course if the volcano erupts by this Saturday.
If not, it is feared Ruapehu will be too volatile.
The run will need to be moved to a 17km contingency course, which would start at the bottom of Ohakune Mountain Rd and finish at the Turoa Ski Fields.
Mr Cameron, the director of Victory Events, said the Whakapapaiti and Mangaturuturu rivers on the designated course could be impacted if a significant eruption.
"The logistics of moving a large number of people across these rivers in a small amount of time holds a risk we and DoC are not prepared to take,'' he said.
"We take the safety of our participants very seriously.
"It is important that we respect the guidelines given to us as a DoC concessionaire in Tongariro National Park and we respect the mountains and their unpredictable nature.''
GNS Science has said changes in measurements at the volcano over the past few weeks showed pressure was building and an eruption was more likely over "the next weeks to months''.
Experts were monitoring activity at the volcano.
The last eruption at Mt Ruapehu was in 2007.
A year earlier, an eruption also occurred and caused a small earthquake near the crater.