VIENNA — Iranian officials sent mixed signals on a plan that would have Tehran ship out most of the material it would need to make a nuclear weapon, with the foreign minister saying Monday that option still exists and a senior diplomat suggesting the opposite.

The contrasting messages appear designed to keep the international community off balance on how far Iran is ready to go in accepting the original proposal — having Tehran export 70 percent of its enriched uranium and having it returned as fuel for its research reactor.