According to the President, over the long run, democracy and economic growth go hand in hand and aid will be directed mostly to governments seen as trying to help their countries climb out of poverty and become self-reliant. As such, the United States will focus their development efforts on countries like Tanzania that promote good governance and democracy, the rule of law and equal administration of justice, transparent institutions with strong civil societies and respect for human rights.
The full speech of President's Obama's address can be read here: http://undispatch.com/obamas-speech-to-the-un-mdg-summit