The only way to reduce our national debt is to grow the economy and cut spending. We have no idea how our money is being spent. As president, I will move all agencies to zero-based budgeting so that every agency has to justify every dollar that they spend.

I didn't say I would cut off all communication with [Vladimir] Putin. What I said was as president of the United States, now is not the time to talk with him.

The highest calling of leadership is to unlock the potential of others.

I think what's fascinating is how many people are playing in politics who maybe haven't played before.

When Iran continues to get away with bad behavior, what do our allies who are Iran's enemies think about us? It is why we cannot stand by while Russia allies itself with Iran. You can't outsource American leadership to Russia. Russia isn't on our side. They're on their side and Iran's side.

When we miss with all the metadata collection we've had, the San Bernardino couple and the Tsarnaev brothers, what that suggests to me is that we are using the wrong algorithms to search through all this data.

I have been tested in many ways, personally, I have beaten breast cancer, I buried a child to addiction. Professionally, you cannot go from being a secretary of nine-person real estate firm to the chief executive of the largest technology company in the world without having been tested over and over and over.