The International Atomic Energy Agency says there are many open questions on the nature and aims of Iran's nuclear program, which could soon include uranium conversion suitable for the building of atomic bombs.

A new report says Iranian technicians have informed the IAEA that they soon plan to test a facility that the IAEA says could convert tons of raw uranium into a substance capable of building several atomic bombs.

The U.S. government, which shared intelligence information with the IAEA, says Iran has a secret nuclear-weapons program and is three to five years away from building an atomic bomb.

Uranium conversion is not banned by the IAEA, but such a move would cast doubt on Tehran's claims its nuclear program is only for peaceful purposes.

A western diplomat speaking on the condition of anonymity said the report shows that Iran is still dragging its feet in cooperating with the U.N. nuclear watchdog and that the pattern of deceit continues.

Iran claims it did no work on an advance centrifuge program from 1995 through 2002, which the IAEA says is not sufficiently backed up and should be further investigated. And the agency says it still has not gotten to the bottom of the origins of contamination found on components in Iran that Tehran claims it imported. The U.N. agency says it is tracking down a vast nuclear black market spanning several continents that supplied Libya with nuclear equipment showing similarities to the Iranian program.

The report on Iran was circulated to diplomats on the 35-member IAEA board that meets in Vienna September 13th to review the Iranian nuclear file.

IAEA spokeswoman, Melissa Fleming, says the investigation of Iran's nuclear program will continues.

"This is a progress report on the findings of the inspectors to date," Ms. Fleming says. "The work still continues. There are still a number of issues that require investigation using all the various methods the IAEA has up its sleeve including environmental sampling."

But a western diplomat who did not want to be named said the IAEA could not go on conducting sampling forever. The diplomat said the time would come for some kind of U.N. involvement.