You have to make change.

I think it's very, very important that in foreign policy and national security decision making, as in any other realm, that there be a range of diversity that reflects the full complexity of America. We should draw on those experiences to inform our decision making.

Well, Nigeria has played a constructive role in peacekeeping in various parts of West Africa. But unless and until Nigeria itself is democratic and respects human rights, it too may well be a source of much greater instability as political repression limits the ability of the people of Nigeria to achieve their full potential.

There are plenty of meetings, receptions, dinners, and so if you are [at the U.N.] any length of time, and I was there for four and a half years, you formed pretty significant relationships with people from all over the world. And that's important to the work you do. If you're trying to rally the General Assembly to vote for something that matters to the United States, those personal relationships count.

I've taken my knocks here and there, but I believe my intentions are good. Doesn't mean everything I do is perfectly executed or I don't make mistakes. Of course I do.

I spend every day up at the United Nations where I have to interact with 192 other countries. I know how well the United States is viewed.

Bashar al-Assad and those who still stand by him are now responsible for the deaths of more than 20,000 in Syria.