A U.N. nuclear safety action plan has been described as "weakened" by diplomats looking for strong measures.
The document from the International Atomic Energy Agency, the third draft presented to IAEA member states over the last few weeks, outlines a series of steps to help improve nuclear safety after the Fukushima Daiichi nuclear accident earlier this year.
The latest version would encourage countries with atomic power to host international safety review missions but puts increased emphasis on the voluntary nature of the proposals.
This has highlighted resistance among many countries against any move towards mandatory outside inspections of their nuclear energy installations.
"There has been a weakening," one European diplomat said of the latest draft. "We are a bit disappointed."
The changes were made following feedback from member state diplomats of the IAEA, and its 35-nation board is expected to debate the final proposal next month in Vienna.
"As thoughts of Fukushima fade slightly, people are less willing to take more concerted action," said another diplomat from a Western country that also wanted firmer action.
The Japan disaster, the world's worst nuclear accident in 25 years, prompted a rethink of energy policy worldwide, underlined by Germany's decision to close all its reactors by 2022 and Italy's vote to ban nuclear power for decades.
Three reactors at the Fukushima Daiichi complex went into meltdown when power and cooling functions failed, causing radiation leakage and forcing the evacuation of some 80,000 people.
Even though IAEA states agree on the need for enhanced nuclear safety in the world, they have voiced differing positions on how much international action is needed.
Diplomats said countries including the United States, India, Pakistan and China were among a group stressing the primary role of national authorities.
Nuclear power plant exporter France was among those seeking stricter international action, they said.
Currently there are no mandatory, international nuclear safety regulations, only IAEA recommendations which national regulators are in charge of enforcing.
The U.N. agency conducts review missions, but only at a member state's invitation.
On the key issue of safety inspections organised by the U.N. agency, the draft action plan was amended to say that member states would be "strongly encouraged to voluntarily host IAEA peer reviews," as such international checks are known.
The previous draft had said countries would "commit to periodically invite peer reviews."
In another section, the old draft said each nuclear energy country would "host at least one IAEA Operational Safety Review Team (OSART) mission during the coming three years."
In the new version the word "voluntarily" was added.
"There are a number of states who simply don't want beefed-up peer reviews," said the Western diplomat.
The IAEA had earlier dropped a numerical target that it would review 10 percent of the world's some 440 reactors in a three-year period and a suggestion that it could select them randomly for inspections.
Today, some 29 states of the IAEA's 151 member countries have nuclear energy, with most reactors in the United States, France, Japan and Russia.
IAEA Director General Yukiya Amano said earlier this month he hoped the agency's annual member state gathering, which takes place the week after the IAEA board meeting, would endorse the action plan.
He said adoption of the measures would lead to a "steady improvement" in nuclear safety.
But the latest IAEA draft removed a sentence which said "robust implementation" of the proposals would "represent a significant step forward in strengthening nuclear safety."