(President Barack Obama laughs during the taping of his appearance on the "Late Show with David Letterman" in New York, Monday, September 21, 2009. Official White House Photo by Pete Souza)

In town for the opening of the United Nations General Assembly on Monday, President Obama also stopped off at the Ed Sullivan Theater to film an appearance on Late Night with David Letterman. Asked President Obama about the state of the economy, the president called the $787 billion stimulus package passed in his first month in office a "tourniquet" that prevented the recession from getting worse. Full economic recovery will take time, Mr. Obama warned, but added that the situation appeared to be getting better, citing the incredible potential for immediate job growth in the clean energy and energy efficiency sectors, just by making buildings more efficient. Something that may have brought a smile to the face of ousted green jobs adviser, Van Jones.

Earlier in the day, speaking at the Hudson Valley Community College in Troy, New York, President Obama unveiled his strategy to "foster new jobs, new businesses, and new industries by laying the groundwork and the ground rules to best tap our innovative potential." Mr. Obama said the strategy begins where innovation so often does: in the classroom and in the laboratory. "Education, infrastructure and research," said Obama, "are the building blocks of innovation." Later on in the address, Obama elaborated on energy:

No area will need innovation more than in the development of new ways to produce and use and save energy. And you understand that here at Hudson Valley. I firmly believe that the nation that leads the clean energy economy will be the nation that leads the global economy.

And that's why we're doubling our capacity to generate renewable energy, building a stronger and smarter electric grid. And I was meeting some young people who are being trained right here so that they're going to be working on creating this smart grid.

We're investing in technologies to power a new generation of clean-energy vehicles. We've helped reach an agreement to raise fuel economy standards. And for the first time in history, we passed a bill to create a system of clean energy incentives which will help make renewable energy a profitable kind of energy in America, while helping to end our dependence on oil and protect our planet for future generations. This bill has passed the House. We're now working to pass legislation through the Senate. It is time to get this done

Watch President Obama on Letterman (one of two clips made available by CBS):

CBS