Gregg warns U.S. could face Greece's budget issues

Historically, those debt-to-GDP ratios are around 25 percent, but the nation is spending too much and taking in too little revenue to avoid sliding into a fiscal crisis, he said. 

"If we allow that to continue, we're essentially going to pass on to our kids a country which is significantly less prosperous and where the standard of living will go down." 

The U.S. should be concerned about what's happening in Europe --- Greece, Ireland, Spain and Portugal -- despite the differences between the economic and deficit structures of those countries, Gregg said. 

"When they get in these problems, not only do they bring that nation down, but they potentially bring a lot of other countries with them and, certainly, affect the value of the euro," he said. "And that's a problem for the world."