U.S. Secretary of State Condoleezza Rice says it is time for Iran to change its tactics on the nuclear issue and stop enriching uranium.

Speaking to reporters in Vienna Thursday - on the sidelines of a women's empowerment conference, Rice said the international community wants Iran to demonstrate that it is not seeking a nuclear weapon.

Despite limited U.N. sanctions and a possibility of a tougher penalties, Tehran has continued to ignore U.N. demands to stop its uranium enrichment -- a process that can be used to make nuclear weapons.

Iran's top nuclear negotiator Ali Larijani and European Union foreign policy chief Javier Solana are to meet in Madrid Thursday for another round of talks to try to resolve issue.

Larijani says suspension of enrichment activity is not a way to resolve the dispute.

On Wednesday, foreign ministers from the Group of Eight industrialized nations: Britain, Canada, France, Germany, Italy, Japan, Russia and the United States, renewed calls for Iran to stop uranium enrichment or face "appropriate measures."

The United States and its allies accuse Iran of trying to develop nuclear weapons. Tehran says its program is for peaceful, civilian use.