Iran is reported to have expanded its nuclear program, despite the threat of United Nations sanctions.
Iran's semi-official student news agency (ISNA) says nuclear engineers have begun operating a second network of centrifuges at a uranium enrichment facility.
The report quotes unnamed sources as saying gas was fed into a second system of cascades this week and that the results of the process already have been obtained.
At the White House Friday, President Bush said the international community must work harder to prevent Iran from acquiring nuclear weapons. Iran says its nuclear program is for peaceful purposes.
Britain, France and Germany have proposed a draft U.N. Security Council resolution that would impose sanctions on Iran for its nuclear program and refusal to suspend enrichment activities.
Russian Defense Minister Sergei Ivanov said he does not share concerns about the report on the second network of centrifuges. He said it is premature to talk about the production of weapons-grade uranium.
However, in Jerusalem, Israeli Prime Minister Ehud Olmert compared the policies of Nazi Germany to Iran's nuclear program and its threats to Israel. He noted Iranian President Mahmoud Ahmadinejad's statement that Israel should be wiped off the map.
French President Jacques Chirac said Friday he supports temporary, reversible sanctions on Iran if talks to end the standoff fail. Mr. Chirac spoke during a visit to China.
In Baku, Azerbaijani President Ilham Aliyev said his country does not support sanctions against neighboring Iran, saying such restrictions are "counterproductive" and would only worsen the situation.
Enrichment of uranium is carried out in lines of centrifuges called cascades and is used to make the fuel for civilian nuclear reactors. But in highly refined form, enriched uranium can serve as the raw material for atomic weapons.
Some information for this report was provided by AFP and AP.