A state of emergency put in place after last month's eruption of Mt Bagana in Bougainville has been extended for the maximum two-month period.
MPs in the autonomous Papua New Guinea region voted on the measure on Wednesday at an extraordinary meeting of parliament.
The original state of emergency was applied to the Torokina and Wakunai districts near Mt Bagana, but it has now been broadened to encompass the south Bougainville districts of Siwai, Buin, and Bana because of weeks of flooding.
President Ishmael Toroama told parliament the immediate measures include the establishment of more evacuation centres, in addition to the two already in use at Torokina and Wakunai.
These will be at Piva Station and the Wakunai district areas, and another two in the Kopani Wards 1 and 2 in the Panguna district, and at Soroken in Kunua district.
He also said the Bougainville Disaster Risk Reduction Management Plan, which outlines strategies for resource allocation and community response to natural and human-induced disasters will be finalised.
Toroama also announced that the Australian government had initiated support for the Rabaul Volcanic Observatory (RVO) to establish a seismic monitoring system at Piva Station.
An RVO team is now in Bougainville and is to be stationed in Torokina district for the next three weeks to install the monitoring instruments.
Mt Bagana erupted for the first time in 11 years on July 7, sending ash and sulphur-laden smoke over a wide area.
This has impacted on water and food supplies, damaged some housing and left several thousand displaced.
There has been a significant international response for which President Toroama has expressed Bougainville's gratitude.