ACT Mount Clear blaze covers 36 hectares

Firefighters battling a bushfire near the NSW-ACT border are preparing for severe conditions forecast for the weekend.

The blaze at Mount Clear, about 80 kilometres south of Canberra, has been burning since Wednesday night and covers 36 hectares.

A dozen helicopters and planes, including a C130 Hercules with a 14,000-litre water capacity, as well as 35 firefighters are trying to extinguish the fire.

The ACT Emergency Services Agency said the immediate objective was to slow the spread of the fire and have it contained.

Ground crews are working on containment lines, while two bulldozers have been deployed to make a trail from the south for fire trucks.

The agency warned severe conditions were forecast for Sunday and could cause the fire to spread to areas of NSW between Michelago and Bredbo.