Washington, May 25 (Xinhua-ANI): The United States on Friday reacted cautiously to a report by the UN nuclear watchdog which cited traces of higher-than-expected purity of enriched uranium in Iran's nuclear site.

Earlier the day, the International Atomic Energy Agency (IAEA) said in its latest report on Iranian nuclear issue that its inspectors have detected traces of up to 27 percent-purity enriched uranium in the country's Fordow nuclear fuel enrichment plant.

With regard to the trace elements at 27 percent, we are aware, obviously, of this finding, said State Department spokeswoman Victoria Nuland at a regular briefing. The purity level is higher than the 20 percent Tehran has said it is enriching.

When asked if Washington found the report disturbing, Nuland declined to characterize it one way or another, insisting that her government will wait for more information from the IAEA regarding the origin of the trace.

Our understanding is that the IAEA is following up with Iranian authorities to better understand the origins of these trace uranium particles that seem to have been enriched at a higher level, she told reporters.

There are a number of possible explanations for this, including the one that the Iranians have provided. But we are going to depend on the IAEA to get to the bottom of it, Nuland said.

According to the report obtained by media, Iran indicated that the production of such particles above the target value may happen for technical reasons beyond the operator's control. (Xinhua-ANI)