Beirut ? Iran’s response Thursday to a proposed deal to transform its nuclear material into fuel for a medical reactor is “inadequate,” a senior Western diplomat said, adding that it failed to address key U.S. and European concerns about Iran’s nuclear intentions.

Iran appeared to seek modifications to the proposal to move most of its enriched uranium to Russia and France to be further refined and shaped for use in a medical reactor.

The proposal would have depleted Iran’s stockpile of nuclear fuel below the threshold necessary for making a single nuclear bomb.

But according to the diplomat, Iran wants to send its uranium abroad in smaller batches over an undetermined stretch of time rather than the lump transfer by year’s end. Such a change would allow Iran to replenish its stock quickly.