United Nations ? The United States didn’t have authorization from the U.N. nuclear watchdog when it secretly shipped from Iraq uranium and highly radioactive material that could be used in so-called “dirty bombs,” U.N. officials said Wednesday.

The nearly 2 tons of low-enriched uranium and approximately 1,000 highly radioactive items transferred from Iraq to the United States last month had been placed under seal by the International Atomic Energy Agency at the sprawling Tuwaitha nuclear complex, 12 miles south of Baghdad, the officials said.

“The American authorities just informed us of their intention to remove the materials, but they never sought authorization from us,” said Gustavo Zlauvinen, head of the IAEA’s New York office.

However, U.S. nuclear authorities said late Wednesday they had Iraqi approval and didn’t need U.N. authorization to move the material.

“We are in custody of the material only, and we have the permission of the Iraqi government to take this out of the country,” said Paul Longsworth, deputy administrator for defense nuclear nonproliferation in the U.S. National Nuclear Security Administration.

U.S. Energy Secretary Spencer Abraham disclosed the secret airlift from Iraq on Tuesday as “a major achievement” in an attempt to “keep potentially dangerous nuclear material out of the hands of terrorists.” The material was taken to an undisclosed U.S. Energy Department laboratory for further analysis.

The airlift ended June 23, five days before the United States transferred sovereignty to Iraq’s new interim government.