UNITED NATIONS (Reuters) - Secretary of State Colin Powell tried on Thursday to explain away remarks on Iraq dating back to the beginning of the Bush administration, before the United States decided to invade Iraq.

Speaking in Cairo in February 2001, on his first Middle East trip, Powell said that Iraq had not developed "any significant capacity" in weapons of mass destruction and was not able to attack his neighbors with conventional weapons.

A Democratic congressional aide dug out his remarks this week and has circulated them to the media.

Asked why he changed his assessment, Powell said: "I didn't change my assessment... I did not say he (Iraqi President Saddam Hussein) didn't have weapons of mass destruction."

"He was a threat then. The extent of his holdings were yet to be determined. It was early in the administration and the fact of the matter is it was long before 9/11 (the date of the 2001 attacks on the United States)," he added.

Powell noted that his objective at the time was to muster international support for a new U.N. sanctions system designed to ease the flow of civilian goods to Iraq while tightening controls over imports of possible military value.

The United States eventually changed the sanctions system but after the attacks the Bush administration gradually shifted its Iraq policy to one of "regime change" by military force.

The main rationale cited for invading Iraq was that Saddam Hussein had weapons of mass destruction and might pass them on to extremist groups like al Qaeda.

But since last March's invasion no one has been able to find any such weapons in Iraq, nor evidence of a link between Saddam and al Qaeda, the group blamed for the 2001 attacks.

"A lot changed between February 2001 (and the invasion), but I don't find anything inconsistent between what I said then and what I've said all along," Powell said.

Speaking in Cairo in 2001 after a meeting with Egyptian President Hosni Mubarak, Powell said sanctions had worked.

"He (Saddam Hussein) has not developed any significant capability with respect to weapons of mass destruction. He is unable to project conventional power against his neighbors. So in effect, our policies have strengthened the security of the neighbors of Iraq, and these are policies that we are going to keep in place," he added.