Amid Reports of Russian Missile Sale

U.S. Sees 'Troubling' Iran Nuclear Moves, Urges Steps by Tehran

U.S. Ambassador to the International Atomic Energy Agency says Washington is ready to work with the new Iranian government 'to reach a diplomatic solution' over Islamic Republic's nuclear program.

The United States said on Wednesday it saw "troubling developments" in Iran's nuclear program and called on the country's new president to take concrete steps soon to ease concerns about Tehran's aims.

Iranian President Hassan Rohani, a relative moderate, has pledged to smooth Iran's relations with world powers to help ease stringent international sanctions imposed on the Islamic Republic over its atomic activities.

U.S. Ambassador to the International Atomic Energy Agency (IAEA) Joseph Macmanus said Washington was ready to work with the new Iranian government "to reach a diplomatic solution that will fully address the international community's concerns" about Iran's nuclear program.

"We are hopeful that the Rohani administration will live up to its assurances of transparency and cooperation by taking concrete steps over the next several months," he told the 35-nation board of the IAEA.

"We are mindful of this unique moment, and urge Iran to take the steps necessary to allay international concerns about the nature of its nuclear program," Macmanus said, according to a copy of his speech.

Iran says it is enriching uranium only for civilian energy and medicine. The West suspects the program is covertly oriented towards developing the capability to make nuclear weapons.

Macmanus noted that Iran had further expanded its uranium enrichment capacity by continuing to install both advanced and first-generation centrifuges, calling these steps "concerning escalations of an already prohibited activity".

Iran is also making further progress in the construction of a reactor, Arak, that can yield plutonium for bombs, including putting the reactor vessel in place and beginning to make fuel, he said. "All of these are troubling developments," he said.

Earlier on Wednesday, The Russian Kommersant daily reported that Russia has agreed to supply Iran with advanced S-300 anti-aircraft missiles and build an additional nuclear reactor at the Bushehr nuclear site.

A "source close to the Kremlin" told the Kommersant that the agreements would be discussed during Russian President Vladimir Putin's visit to Tehran on Friday. Putin is set to meet with high-ranking Iranian officials, including President Rohani.