U.N. nuclear watchdog urges Iran access as talks start VIENNA (Reuters) - A senior U.N. nuclear watchdog official said Iran needed to give his inspectors access to information, people and sites as he began a two-day meeting with Iranian officials on the Islamic state's disputed atomic activities on Monday. Herman Nackaerts, deputy director general of the International Atomic Energy Agency, told reporters as he arrived at an Iranian diplomatic mission in Vienna that Iran should now engage on issues of substance with the IAEA. The U.N. agency is investigating suspicions that Tehran may be seeking nuclear weapons capability, a charge it denies. "The aim of our two days is to reach agreement on (an) approach to resolve all outstanding issues with Iran, in particular clarification of the possible military dimensions remains our priority," Nackaerts said. Two previous rounds of talks in Tehran early this year failed to make any notable progress, especially on the IAEA's request for access to a military site where it believes nuclear weapons-relevant research may have taken place. Since then, Iran and the six world powers have resumed wider diplomatic talks aimed at resolving the standoff over Tehran's atomic ambitions and they will meet again in Baghdad on May 23. Western diplomats will be watching this week's discussions in Vienna for any sign that Iran is now ready to address the IAEA's concerns about its nuclear work, saying this would send a positive message ahead of the Baghdad talks. "We are here to continue our dialogue with Iran in a positive spirit," said Nackaerts, who heads a team of senior IAEA officials in the meeting at the Iranian diplomatic mission. "It is important now that we can engage on the substance of these issues and that Iran let us access to people, documents, information and sites," he said. Reporting by Fredrik Dahl; Editing by Alison Williams