The United Nations Special Rapporteur on toxic waste says the communities affected by the nuclear tests in the Marshall Islands feel like nomads in their own country.
The United States tested 67 nuclear weapons at Bikini and Enewetak from 1946-1958.
Calin Georgescu, who has ended a four-day visit to the Marshalls, says his fact-finding mission focussed on the human rights issues associated with the nuclear tests.
Mr Georgescu says as a result of the tests, all of these communities have suffered dislocation, in one form or another, from their indigenous way of life.
He says one message came across quite clearly from the people he met.
"They are look to return to their homelands, the land for them is their life, and the atolls, many of them, they are not still safe."
Calin Georgescu says the governments of both the Marshalls Islands and the US bear the responsibility to find effective redress for those islanders affected by the weapons testing.
Mr Georgescu's visit will result in a report to the United Nations Human Rights Council in September.