Marshall Islands President Christopher Loeak called on the United States Saturday to resolve the "unfinished business" of its nuclear testing legacy in the western Pacific nation.

Compensation provided by Washington "does not provide a fair and just settlement" for the damage caused, he told a ceremony in Majuro marking the 60th anniversary of the devastating hydrogen bomb test at Bikini Atoll which contaminated many islands with radioactive fallout.

"We remain the closest of friends with the United States, but there is unfinished business relating to the nuclear weapons testing that must be addressed."

Loeak said the unfinished business not only affected the four atolls that the United States acknowledged as exposed, but also many other islands throughout the country.

In 1983, 29 years after the March 1, 1954 explosion, a compensation agreement was reached in which Washington provided the Marshall Islands with $150 million to settle all nuclear test claims.

But more than 10 years later, during then president Bill Clinton's administration, formerly secret documents about the nuclear tests were released and confirmed dozens of islands were exposed to the fallout

Loeak called this "dramatic new information" that had not been revealed to Marshall Islands negotiators.

"It is abundantly clear that the agreement was not negotiated in good faith and does not provide a fair and just settlement of the damages caused," he said.

US ambassador Thomas Armbruster, who delivered prepared remarks in both English and Marshallese languages, said "words are insufficient to express the sadness" of the 60th anniversary of the nuclear test.

But, because of the nuclear weapons tests, "today we live in a safer world", Armbruster added.

The United States is continuing to work with the Marshall Islands to provide health care and environmental monitoring of several affected islands, he said.

Bikini islander Hinton Johnson criticised the level of compensation the displaced Bikinians receive from the US-provided funds.

"Today, each person receives $46 per month or a little over one dollar per day," he said during the ceremony.

Although the Nuclear Claims Tribunal had awarded the Bikinians more than $560 million in compensation and nuclear test clean up funding, there was no fund to pay them from, he said.

"We ask the US and Marshall Islands governments to provide the money for the tribunal's award for the time we've been homeless and unable to return to our homeland," Johnson said.