TROOPER Jason Brown, the 18th Australian soldier to be killed in Afghanistan - and the seventh this year - was a third-generation Digger who served three tours in East Timor before realising his dream of joining the elite SAS regiment.

Yesterday Prime Minister Julia Gillard and Opposition Leader Tony Abbott paid tribute to Trooper Brown, 29, but said his death at the hands of Taliban fighters would not alter Australia's commitment to staying the course in the nine-year war.

Killed in Afghanistan ... Trooper Jason Brown.

The shattered family of Trooper Brown were being supported by relatives and Defence Force staff at their home in Thornleigh, in Sydney's north, last night.

The former army commando with extensive experience in East Timor had been in action with the covert SAS for just 2½ months. He died of multiple gunshot wounds after a battle in Kandahar province.