A question of UN parliamentary procedure...

I’ve noticed that whenever Blix or Powell makes a report to the UN, he reads a speech, then other nations on the Security Council respond with their pre-written speeches.

How come nations can’t question the “original speaker” on his/her report (along the lines of a U.S. Senate confirmation hearing, or when the British PM has to answer questions in Parliament)?

Or does this happen when I’m not watching?

Seems like if Blix or Powell had to respond to tough questions, the debate in the UN may be more legitimate.

Or am I completely off base?