World powers have told Iran the "door remains open" for talks on the country's disputed nuclear program.
The five permanent members of the U.N. Security Council and Germany -- the so-called P5 + 1 -- repeated the invitation on Wednesday at an International Atomic Energy Agency (IAEA) meeting in Vienna.
Russian envoy Grigory Berdennikov said world powers expect Iran to show what he called a "pragmatic attitude" and respond positively.
The United States and many other countries suspect Iran is using its nuclear program to develop weapons. Tehran denies this, saying the program is for peaceful purposes only.
The last round of nuclear talks with Iran ended in January with no substantive results.
On Tuesday, Iran's foreign ministry said the IAEA was being pressured when it criticized the country's nuclear program this week.
EU representatives attending the IAEA meeting expressed similar concern Wednesday about that program.
Separately, Iranian Nobel peace laureate Shirin Ebadi predicted there would be a popular anti-government revolt in her country, similar to those sweeping through much of the Middle East.
But she said she hopes the uprising will be peaceful -- unlike in Libya. Ebadi commented Wednesday on the sidelines of a U.N. Human Rights Council meeting in Geneva. The exiled human rights activist has been urging world powers to freeze the assets of Iranian officials.