US legislation banning contracts for Russian-made space rocket engines displeases both the supplier in Russia and consumers in the United States, the press secretary of Russia's design bureau Energomash, told Sputnik on Thursday.

On Wednesday, media reported that the Pentagon is in favor of easing the ban on Russian-made space rocket engines. In December 2015, the US House of Representatives adopted an amendment by Sen. John McCain, banning the use of Russian-made rocket engines RD-180 until 2019.

The United Launch Alliance (ULA), a joint Boeing-Lockheed Martin venture providing rocket launch services to the US government, uses the Russian RD-180 rocket engines to power the Atlas V launch vehicles into space.

"People are working, people have certain tasks. Then, all of the sudden, come the sanctions that not only interrupt business, they interrupt the common useful cause. Of course, they [ULA] are also displeased," Ekaterina Zhdanova said.

The discontent of Energomash, that produces the engines, and the ULA, is "quite explainable as the people [in these companies] are actually working on something," Zhdanova concluded.

On May 15, US Senate Armed Forces Committee Chairman John McCain stated that the United States plans to manufacture its own rocket launcher engine in order to replace RD-180s by 2017.

The Russian-built RD-180, the successor to the Soviet RD-170, was first installed on a US Atlas III launch vehicle in 2000. It is now routinely used on Atlas V carrier rockets.