A high-ranking delegation from the International Atomic Energy Agency (IAEA) arrived in Tehran on Monday for talks on the relevant issues of Iran's nuclear program.

According to local satellite Press TV, the delegation, headed by IAEA's chief inspector Herman Nackaerts, arrived in Tehran in the early hours of Monday for two-day talks.

In January, the IAEA sent a high-level team to Iran for the first round of talks with the country's officials over nuclear issues. Iran's media reported that the delegation, headed by Nackaerts, did not visit or inspect any nuclear site in Iran. The spirit dominating the three-day talks was "positive and constructive," Iran's official IRNA news agency said.

United Nations General-Secretary Ban Ki-moon said Friday that Iran should fully cooperate with the IAEA in order to clarify controversial aspects of the country's nuclear program.

"I am deeply concerned by the latest IAEA report indicating that there may be the possibility of a military dimension in Iranian nuclear development programs," Ban told a press conference in Vienna.

Ban said that he has been urging Iranian President Mahmoud Ahmadinejad and all senior authorities of the Iranian government that "the onus is on the Iranian side to prove, to convince the international community that their nuclear development program is genuinely for peaceful purposes."

Meanwhile, Ban said all outstanding issues should be resolved peacefully through negotiation and dialogue. "There is no alternative to peaceful resolution on this issue," Ban stressed.