Russia and France are calling on Iran to stop all uranium enrichment.
The two countries issued their statement Tuesday during a visit to Moscow by French Prime Minister Dominique de Villepin.
Iran resumed small-scale uranium enrichment Monday -- an initial step in the process of producing fuel for nuclear reactors or atomic weapons. Iran had threatened to resume enrichment after the International Atomic Energy Agency referred it this month to the U.N. Security Council for possible sanctions.
China, another permanent member of the U.N. Security Council, called Tuesday for continued diplomatic efforts to ease growing tensions over Iran's nuclear program.
U.N. Secretary-General Kofi Annan, who met with President Bush in Washington Monday, said he hopes there will be no steps to escalate the situation.
Iran denies Western charges that it is trying to build atomic weapons.
Some information for this report was provided by AFP, AP and Reuters.