The nexus between terrorism and nuclear weapons, or even nuclear material, is obviously a current concern.

The other countries did not share the same concern the United States had in the early '90's - that North Korea actually had an ongoing nuclear weapons program.

So the president set out the policy guidance and said it had to take place in a multilateral fashion so that other countries in the region could be invested in the success of this process.

But with lots of good ideas, implementation is the key, and so we need to keep our eye on the ball as we go forward and make sure that people honor their pledges in terms of financial commitments, and that we actually use this money so that it makes a real difference.

You have to play the cards you are dealt and if it has made it harder, it doesn't matter, you still have to get the deal done.

Now North Korea certainly is located in a different place geographically, but I think it faces the same type of strategic decision. Does it want a different future for its people?

Any agreement that you have isn't going to be based on North Korea's intentions or trust.