The West, especially the United States, is to blame for the failure of the Syria peace plan worked out by Kofi Annan, Iranian Foreign Minister Ali Akbar Salehi said on Friday, state media reported.
"The West and some regional countries did not want Annan to succeed," he said, quoted by the official IRNA news agency.
"Every time Mr Annan sought to resolve the Syrian crisis, the West created obstacles."
Salehi said Annan's resignation on Thursday as UN-Arab League envoy because of lack of support within the UN Security Council was due to intransigence by the United States, not by Russia and China as US officials have asserted.
"The lack of unity in the Security Council that Mr Annan spoke of is not about China or Russia; the Americans are turning it around and pinning it on them. They seek to impose their own ideas and they do not (want) to speak the truth."
Salehi added that Annan's six-point peace plan had been accepted by Syria and other regional countries, but those nations supporting Syria's rebels "did not let Mr Annan succeed in implementing his plan."
He also said he hoped any successor to Annan as envoy would work as "independently" as Annan did, and warned that any Western-aligned envoy "would fail, because the other side would not cooperate with him."
Iran, Syria's key ally in the Middle East and the main supplier of political, economic and humanitarian support to Damascus's beleaguered regime, claims the United States and Israel are colluding with pro-US Arab states and with Turkey to back the rebels.
"The United States, Israel, Saudi Arabia, Turkey and Qatar are working hand-in-hand to overthrow (the regime in) this country," Ayatollah Ahmad Janati, the head of Iran's influential Guardian Council, said as he led Friday prayers in Tehran.
"Who doesn't know you are directly interfering in Syria?" Janati asked.
US officials in return accuse Iran supplying military aid to the forces of Syrian President Bashar al-Assad, something Tehran denies.
Iran's foreign ministry spokesman, Ramin Mehmanparast, said on Friday during a trip to China that the "interfering countries" made Annan's mission fail, and he implied that Iran could now be among some countries to step up and try to solve the conflict.
"Independent countries in the region will now have a more crucial role" to play, and ""should prepare the ground for dialogue between the (Syrian) government and the rebels," he was quoted as saying.