By Laurent Lozano
"Iran, in the one-on-one meeting, was the majority of the conversation," Mike McFaul, a top adviser to Obama on Russian affairs, told journalists after the Kremlin talks between the US and Russian presidents on Monday.
"There's a reason for that, because that is something that affects our real national security interests," he said.
Another top official travelling with Obama on his visit to Moscow, Deputy National Security Advisor Denis McDonough, said the Russian president made plain to his guest that Moscow's concern about Iran was rising.
"I think the president has been struck by the candor with which President Medvedev has underscored his concern about the growing threat from Iran," McDonough said.
Russia is building a nuclear reactor in Iran for the Iranian atomic programme, which Tehran insists is strictly for energy production but the United States fears could be used to manufacture an atomic bomb.
Iran — whose president has called for Israel to be wiped from the map — also possesses missiles capable of reaching targets throughout the Middle East that could be fitted with nuclear warheads if Tehran possessed them.
Iranian officials consistently deny any intention to acquire nuclear weapons but insist their country has a sovereign right, like any other, to pursue peaceful nuclear energy development.
The United States and Russia have for years differed sharply on how to approach the Iran security issue, which is also directly linked to their disagreement on US missile defence plans in Europe.
When the previous US administration of president George W. Bush introduced the programme, Washington said it was to protect against missile attacks by "rogue states" such as Iran.
But the US officials indicated they saw signs of movement on both topics during Obama's closed-door discussions with Medvedev on Monday.
"I think one of the important and one of the most significant things that developed today was a Russian acknowledgment that we need to study the growing ballistic missile threat," another top Obama aide, Gary Samore, said.
"That joint assessment is going to be focused on Iran and North Korea as the two countries which pose the most direct threat to the US and its allies and to Russia as well," he said.
During a joint news conference with Obama after their meeting, Medvedev did not mention Iran once.
But the Russian leader stated: "There are negative trends in the world and they are due to the emergence of new nuclear players.
"It is our common, joint responsibility and we should do our utmost to prevent any negative trends there…. Our negotiations with President Obama have demonstrated that we share the same attitude towards this problem."
Washington has for years argued that it needs to fortify missile defences in Europe precisely to defend allies from such a threat.
Moscow however has previously rejected that argument, saying it has seen no evidence Iran is working to develop nuclear weapons and that Iran currently has no missile capable of reaching the European allies the US system would protect.
The White House detected a shift in the Russian stance on Iran, said McFaul.
"Just remember, if they wanted to have an adversarial relationship with us with Iran right now, there are all kinds of things they could do very easily that would make our situation a lot worse there.
"And they're not doing those things."
