WASHINGTON, March 13 (UPI) -- The U.S. Food and Drug Administration is trying to halt the import of electronic cigarettes into the United States.

The FDA told CNN it considers so-called e-cigs an unapproved new drug..

The makers of the cigarettes, which are white with a brown filter and tip that glows red, say the cigarettes are safe because they don't contain tar or other chemicals. They do, however, contain liquid nicotine.

Elicko Taieb, CEO of Smoking Everywhere, a major distributor of electronic cigarettes, compared the cigarettes to a nicotine patch. "There are no ingredients in our e-cigs that can cause cancer. However, it is a pretty new product, so we are not 100 percent sure of the side effects at this point," Taieb told CNN. "But we haven't heard of any negative side effects yet, but we are pretty sure they are safe."

The World Health Organization has called for clinical studies and toxicity analysis to determine the safety of the cigarettes, CNN said.