WASHINGTON — The Obama administration on Friday said it is exasperated with Iran for holding up new talks with world powers over its disputed nuclear program.

Negotiations had been envisioned for next week. But State Department spokeswoman Victoria Nuland said the US and its partners have been “surprised that the Iranians keep coming back again and again with new preconditions, new dates and venues.”

She says consultations with Iran continue on finding a city and date for a meeting.

The US complaint echoes that of the European Union, which suggested earlier this week that Iran was willfully delaying the talks.

Also on Friday, Israeli UN ambassador Ron Prosor accused Iranian President Mahmoud Ahmadinejad of denying the Holocaust “while threatening to carry out another one.”

In a speech marking International Holocaust Day, Prosor warned that Iran and Hamas were teaching the next generation that the Holocaust “is a lie made up by the Zionists,” imbuing them with anti-Semitism.

“Our duty has never been clearer. The hands of time threaten to cloud the world’s memory. It is our responsibility to rescue the history and lessons of the Holocaust,” said Prosor.

The US and many other countries fear the Islamic republic may be trying to develop nuclear weapons. Tehran says its program is for peaceful purposes.