The U.N secretary-general withdrew his invitation to Iran to join this week's Syria peace talks, saying he is "deeply disappointed" by Iran's statements Monday.
A spokesman for Ban Ki-moon announced the withdrawal less than 24 hours after Ban surprised the U.S and others by saying he had invited Syria's closest regional ally.
The invitation was withdrawn shortly after Iran's U.N ambassador declared the Islamic Republic wouldn't join the Syria talks if required to accept the roadmap sketched during a 2012 Geneva conference on Syria.
A spokesman for Ban "Martin Nesirky" said senior Iranian officials had assured Ban that Iran understood the terms of his invitation, noting that "the Secretary-General is deeply disappointed by Iranian public statements today that are not at all consistent with that stated commitment".
Nesirky said Ban" continues to urge Iran to join the global consensus behind the Geneva Communiqué".
The talks are set to begin Wednesday in the Swiss city of Montreux, with delegations from the United States, Russia and close to 40 other countries attending. Face-to-face negotiations between the Syrian government and its opponents - the first since the three-year crisis began -start Friday in Geneva.
But Ban's announcement Sunday night that Iran was invited to Montreux angered Syria's main Western-backed opposition group, which over the weekend had announced it would join the talks after intense international pressure.
The opposition set a Monday afternoon deadline, saying Iran had to commit publicly by 1900 GMT Monday to the terms set in the 2012 Geneva talks - the formation of a transitional government for Syria that would pave the way for democratic elections -or the U.N should withdraw the invitation.
Senior U.S. officials also said Ban's invitation had to be withdrawn unless Iran fully and publicly endorsed those terms.
Invitations to the Montreux meeting had been subject to approval by the initiating states, Russia and the United States, but the two countries had been at an impasse over Iran.
Iran's U.N. ambassador on Monday issued a statement on Iranian participation in this week's peace talks on Syria, saying that Iran will definitely not take part if it is required to accept a June 2012 deal agreed in Geneva.
"If the participation of Iran is conditioned to accept Geneva-1 communique, Iran will not participate in Geneva-2 conference", Iran's U.N. Ambassador "Mohammad Khazaee" said in a statement after Ban Ki-moon suggested he was reconsidering his invitation to Iran to attend the talks.
The Geneva-1 communique, agreed in June 2012, called for a political transition in Syria .
Ban earlier said he was disappointed that Iran had made statements repudiating Geneva-1 after telling him it could accept the June 2012 deal.