U.S. Secretary of State Condoleezza Rice says the United States is concerned about Iran's threats to share its nuclear technology.
She says sharing such information with other countries adds to international concerns over the fact that Iran itself has the technology.
Earlier Tuesday, Rice said Iran is deepening its isolation by threatening to suspend ties with the International Atomic Energy Agency. She added the United States prefers resolving the dispute over Iran's nuclear program through diplomacy.
Rice discussed Iran during stops in Greece and Turkey. In Ankara, she and Turkish Foreign Minister Abdullah Gul also spoke about the need to prevent Kurdish militants from using Iraq as a base to launch attacks on Turkey.
In Athens, Rice met with Greek Foreign Minister Dora Bakoyannis and Prime Minister Costas Karamanlis. She urged more efforts to resolve the division of Cyprus.
Rice was greeted in both Athens and Ankara by crowds of protesters. In Athens, police used tear gas to disperse thousands of demonstrators who hurled gasoline bombs and rocks at authorities.
After Turkey, Rice heads to Bulgaria.
Some information for this report was provided by AFP, AP and Reuters.