Ukraine is among the Eastern European countries eyeing shale gas reserves. In January, Shell Chief Executive Officer Peter Voser signed a $10 billion contract to explore Ukrainian shale.
U.S. Ambassador to Ukraine John Tefft was quoted by National Radio Co. of Ukraine as saying concerns are justified, but only if shale campaigns are reckless.
"I've always been a supporter of environmental protection," he said. "And I am convinced (that) if shale gas is extracted in an appropriate manner, this can be done without harming the environment."
Critics of hydraulic fracturing, known also as fracking, have expressed concern that some of the chemicals used in the process may leach into the groundwater. Fracking is also a water-intensive extraction procedure.
Ukraine is searching for ways to wean itself from Russia as a main energy supplier. The government estimates that Shell is targeting an area said to contain about 4 trillion cubic feet of shale natural gas.