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.

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

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.

There is a different future that is available to North Korea, if they choose differently.

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