We have important things to talk to the Russians about, despite their meddling in our elections. I hope they're talking about a way to eventually end this horrific humanitarian crisis in Syria, end that war. The Russians have more leverage than we do. I hope they're talking about the fact that, if Kim Jong-un's long-range missiles can reach Alaska one day, they can also reach Vladivostok.

When somebody underestimated me, it made me want to prove them wrong.

I get letters from kids from all over the country. I always try to answer them because there were people I looked up to in my youth and just wanted to be in contact with. It's also important to realize that you find your role models in a lot of different places. I've never believed that your role models have to look like you. You can find them in all sort of colors, shapes and sizes.

I use the word power broadly. Even more important than military and economic power is the power of ideas, the power of compassion, and the power of hope.

You can never ask others to do something you would not do. That is integrity.

I do have a favorite Zeppelin song, Larry, Black Dog.

It's important to Russia to be able to attract capital and to attract technology to develop their oil fields, their oil and gas fields, many of which suffer from lack of access to the very best technologies. And it's also important, and this has been the US government's view to have diversification of supply, diversification of supply roots and, of course, diversification in terms of alternative energy.