DUBAI — Foreign Minister and chief negotiator Mohammad Javad Zarif voiced hope Iran and world powers can agree at talks this week on a roadmap toward defusing the stand-off over Tehran's nuclear activity, but warned the process would be complex. The negotiations about Iran's nuclear program, to start in Geneva on Tuesday, will be the first since the June election of President Hassan Rohani, a relative moderate who wants to thaw Iran's icy relations with the West to secure the removal of punitive sanctions that have hobbled its oil-based economy. Western nations believe Iran's uranium enrichment program is covertly meant to achieve a nuclear arms capability. Tehran denies this, saying it wants only to master nuclear technology to generate electricity and carry out medical research. “Tomorrow is the start of a difficult and relatively time-consuming way forward. I am hopeful that by Wednesday we can reach agreement on a road map to find a path towards resolution,” Zarif said in a message posted on his Facebook account late on Sunday. “But even with the goodwill of the other side, to reach agreement on details and start implementation will likely require another meeting at ministerial level.” Rohani's election in June to succeed conservative hardliner Mahmoud Ahmadinejad has raised hopes of a negotiated solution to a decade-old dispute over the program that could otherwise kindle a new war in the tinderbox Middle East. “We will see if there is a way to transform this new attitude into gestures, but up to now, beyond the new attitude, there has been a total absence of anything that takes us forward on the fundamentals,” a Western diplomat said. “We're expecting that things are more open, but at the same time more complicated as we'll have to study what they are offering,” said the diplomat, who declined to be named. The diplomat added that if the Islamic Republic failed to put any serious new proposal on the table “after all this talk, then they have a serious problem”. Zarif's deputy on Sunday rebuffed the West's demand that Iran send sensitive nuclear material abroad but signaled flexibility on other aspects of its atomic activities, including the degree of uranium enrichment, that worry global powers. Tehran says it needs uranium refined to 20 percent fissile purity to produce isotopes for medical care. But the powers are wary that 20 percent is only a short technical step away from bomb-grade uranium and such a stockpile could give Iran a quick route to weaponisation without stricter limits on its activity. Iran also wants the six powers - the United States, Russia, China, Britain, France and Germany - to recognise what it regards as its sovereign “right” to enrich uranium. — Reuters