All asylum claims by refugees on Nauru will be processed within the next week, with the Nauru government announcing "detention has ended" on the Pacific island.

Nauru Justice Minister David Adeang made the surprise announcement today, which will affect more than 650 refugees, the ABC reports .

"The start of detention-free processing is a landmark day for Nauru and represents an even more compassionate program, which was always the intention of our government," Mr Adeang said.

The Australian-funded camp will become an "open centre" 24 hours a day, with all restrictions lifted.

Detainees will still eat, sleep and receive medical services at the centre.

The centre was reopened in 2012 and is currently home to 653 detainees, including 93 children.