Iran is planning to install new equipment at its main nuclear enrichment facility that could refine uranium much faster than its current machines.
Diplomats speaking to Western news media on the condition of anonymity said Thursday Iran has notified the International Atomic Energy Agency that it wants to install the modern centrifuges at the Natanz site in central Iran.
Natanz contains an underground plant with thousands of centrifuges for purifying uranium for use as a nuclear fuel. Low-enriched uranium can be used to fuel nuclear power plants, while highly enriched uranium is needed for nuclear weapons.
Iran says its nuclear program is strictly for peaceful purposes.
Iran and the so-called P5+1 contact group - the United States, France, Russia, China, Britain and Germany - last held negotiations in June, but the talks broke apart with neither side yielding on its demands.
European Union foreign policy chief Catherine Ashton Thursday said international negotiators will continue efforts to persuade Iran to discuss concerns about its nuclear program.
"We've been saying to the Iranians that we want to propose dates and venues in order that we can get the discussions moving as soon as possible."
Ashton added she is confident a meeting will happen soon.
The United Nations Security Council has demanded in multiple resolutions that Iran suspend all enrichment-related activities and allow U.N. inspectors to access its nuclear facilities.
An IAEA team visited Iran two weeks ago in a bid to reach a deal with Iranian officials on a structured approach for resolving questions about possible military dimensions of the country's nuclear program.
The chief IAEA inspector, Herman Nackaerts, said the "intensive discussions" did not produce an agreement. But he said another round of talks will take place February 12 in Tehran.