Iranian President Mahmoud Ahmadinejad cancelled his visit to New York to address the U.N. Security Council because of delays in granting visas to his entourage, Tehran’s U.N. ambassador said on Friday.

Ahmadinejad had wanted to address the council before it votes on imposing new sanctions on Iran for its nuclear program. The meeting is expected to be held on Saturday, although it has not yet been officially scheduled.

No sooner was the announcement made than Iran and the United States entered into a spat on when and to whom visas had been issued. Tehran said the visas were issued too late and the U.S. State Department said completed applications were not received in time.

The United States issued visas in two batches on Friday at its embassy in Berne, Switzerland, but Iran’s U.N. Ambassador Javad Zarif said that was too late.

“There was no time for the visas to be sent to Tehran in time for the president to be able to fly to New York,” Zarif told Reuters. But he said Iran’s foreign minister, Manouchehr Mottaki, who received his visa early on Friday, would take a commercial flight to New York to address the council.

In Berne, a spokesman for the U.S. Embassy said some 38 visas had been issued early on Friday, including one for Ahmadinejad, and an additional 40 for the entourage late in the day once all the paper work had been completed.

But Zarif said the later batch, which included air crew, was not issued until 5:45 p.m. local time, which did not leave enough time to get the passports back to Tehran in time for the president’s plane to take off.

In Washington, the U.S. State Department said the reasons for the cancellation were a ruse.

“Rather, it would appear that he is unwilling to stand before the Council and take the heat for his continued defiance of the international community,” said spokesman Tom Casey.

Casey said the visas were issued late Friday afternoon “despite the fact that the completed applications for many of them were not received until this morning.”

And at the United Nations, the American representative, Alejandro Wolff said, “I think this is all a pretext. The visas were issued in ample time.”

But in Tehran, Foreign Ministry spokesman Mohammad Ali Hosseini was quoted on television as saying, “Due to the obvious negligence in issuing a visa for members of the Iranian delegation accompanying the president and the plane crew, American officials stopped the president from attending the Security Council’s meeting.”