The unsealed road is difficult to maintain and often in a poor state.
The works are expected to bring 135 jobs, with an Indigenous employment target of 29% included.
Work is set to start on the build of the Dripstone Steam centre in December.
Joyce says the port at Middle Arm will be key to national security and economic growth.
NT mines minister Manison says come to the Territory for the next big resource development.
Gunner says the NT is Australia's comeback capital.
NT environment bill under review as government seeks to cut red tape and entice investors.