When it comes to telephone calls, nobody is listening to your telephone calls. That's not what this program is about. ... What the intelligence community is doing is looking at phone numbers, and durations of calls; they are not looking at people's names and they're not looking at content. ... If the intelligence committee actually wants to listen to a phone call they have to go back to a federal judge, just like they would in a criminal investigation.

If you think that we've overregulated in the environmental space what I can show you is that we have tripled the amount of wind power in this country, increased by tenfold the amount of solar power. We are producing as much oil and gas as we've ever produced.

My wife has been my closest friend, my closest advisor. And ... she's not somebody who looks to the limelight, or even is wild about me being in politics. And that's a good reality check on me. When I go home, she wants me to be a good father and a good husband. And everything else is secondary to that.

Ultimately, I remain optimistic about not just America's future, but the direction that the world is growing.

Iran will for sure have pledged to the international community that it will not develop a nuclear weapon, and now will be subject to an additional protocol, a more vigorous inspection and monitoring regime that lasts in perpetuity.

What is certainly true is that the American people, just like the German people, just like the British and people around the world, are seeing extraordinarily rapid change. The world is shrinking, the economies have become much more integrated and demographics are shifting.

Chancellor [Angela] Merkel is perhaps the only leader left among our closest allies that was there when I arrived. So in some ways we are now the veterans of many challenges over the last eight years.