Obama visits green tech expo in Sweden

"Congratulations. It's a great story to tell. We're very proud of your work,” the president said in response, according to pool reports.

Obama then met with a trio of professors who were working on fuel cell technology for vehicles.

The car looked like a “low-to-the-ground bicycle with three wheels,” according to the pool report. Obama remarked to a “slender woman” that, “You could get in this, but not me.”

But Obama’s concern wasn’t about fitting inside the vehicle — it was about how to get others into them.

A proponent of electric- and alternative-fuel vehicles, Obama told the professors that charging infrastructure in the United States is still a concern for many motorists.

"In the United States, one of the challenges has to do with distribution ... if I was going shopping, where am I gonna refuel, right?” he said, adding, "It's sort of a 'chicken and egg' question."

The president wrapped up his tour by meeting with the Volvo Group to discuss its plans for hybrid plug-in mass transit systems, such as for city buses.

Volvo is planning to launch the “fully electric and emissions free” buses in 2015.

The president inquired about how cost-effective the vehicles would be, to which the Volvo representatives responded the buses would pay for themselves in “10 years, easily.”