Nuclear energy experts and officials have repeatedly warned the Ukrainian authorities that it would be unsafe to use US-made fuel in reactors of Soviet and Russian design.
"Today, an agreement with Westinghouse to increase nuclear fuel supplies to Ukrainian nuclear power plants is being signed in Brussels," Yatsenyuk said.
Relations between Russia and Ukraine, including cooperation on nuclear energy, have soured amid the conflict in Ukraine, which prompted Kiev's turn to US nuclear fuel makers for some of its power plants.
This decision has raised security concern after the fuel sourced from Westinghouse had dangerously malfunctioned at power plants in the Czech Republic. In 2006, a Czech nuclear power plant operating Soviet-designed reactors experienced depressurization with the Westinghouse fuel, leading to its suspension of cooperation with the company.