Iraq's parliament says more than $18bn have gone missing from government coffers.

The US facilitated the release of $20bn to Baghdad after the 2003 invasion -- money derived from Iraq's previously frozen assets and oil revenues, which had been withheld from the Iraqi government because of international sanctions.

Now Iraqi officials say the US needs to provide answers about where the money has gone.

Al Jazeera's Jane Arraf has the story from Baghdad.