'A year or more away'

Obama's comments come after his historic phone call to Iranian President Hassan Rouhani last week, the first direct contact between US and Iranian leaders in more than 30 years. In recent weeks, Rouhani has upped his push for dialogue with Western nations, particularly the US, aimed at resolving a dispute over Iran's nuclear program and the resulting international sanctions against the country.

Obama told the Associated Press that it remained to be seen whether Rouhani would follow through on his initiative, and that Washington would "test" the offer of serious talks.

"Rouhani has staked his position on the idea that he can improve relations with the rest of the world. And so far he's been saying a lot of the right things. And the question now is, can he follow through?" said Obama.

The US president believed there was still at least one year before Iran reached nuclear weapons capability.

"Our assessment continues to be a year or more away, and in fact actually our estimate is probably more conservative than the estimates of Israeli intelligence services," Obama said.

Following his talk with Rouhani, the US president then hosted Israel's prime minister Benjamin Netanyahu at the White House on Monday. Israeli officials contend that Iran is just months away from being able to build a nuclear bomb.

In a speech to the UN this week, Netanyahu warned that Israel would use military action if necessary to defend itself against any nuclear threats from Iran, but such action would be highly unlikely during negotiations between Iran, the US and world powers.

Obama also hinted on Saturday that the Rouhani was not even the final authority on the nuclear issue in Iran.

"He is not the only decision-maker. He's not even the ultimate decision-maker," Obama said, referring to the control of Supreme Leader Ayatollah Ali Khamenei, who has the final say on all government decisions.

Khamenei criticizes Rouhani

In his first comments since Rouhani's visit to the UN General Assembly last week, Khamenei has criticized some of Rouhani's efforts to improve relations with the United States, but offered his qualified backing.

Khamenei said on Saturday "that some of what happened during the New York trip was not appropriate," widely understood to be a reference to Rouhani's 15-minute phone call to Obama.

Khamenei also took the opportunity to express his disdain for Washington.

"We are skeptical of Americans and have no trust in them at all. The American government is untrustworthy, arrogant, illogical and a promise-breaker. It's a government captured by the international Zionism network," he said.

At the same time, though, Khamenei expressed support for much of what Rouhani tried to achieve during his trip.

"We support the government's diplomatic moves including the New York trip because we have faith (in them)," he said.

jr/rc (AP, AFP, Reuters)