Looked to me like he praised them right off the top, and throughout most of his speech.
Here's the one place where the President called the U.N. to task:
It undermines the credibility of this great institution, for example, when the Commission on Human Rights offers seats to the world's most persistent violators of human rights. The United Nations depends above all on its moral authority and that authority must be preserved.
But earlier he said this:
These commitments — hope and order, law and life — unite people across cultures and continents. Upon these commitments depend all peace and progress. For these commitments we are determined to fight.
The United Nations has risen to this responsibility. On the 12th of September, these buildings opened for emergency meetings of the General Assembly and the Security Council. Before the sun had set, these attacks on the world stood condemned by the world.
And I want to thank you for this strong and principled stand.
He's giving the United Nations credit for the international condemnation of the assault on America.
Are the other nations of the world so hostile to us and so without character whatsoever that they were actually waiting on the United Nations to force a condemnation out of them?
His worshippers can call his speech an exercise in diplomacy. I saw it as a waste of his time and my money.