MOSCOW, December 24. /TASS/. Russia’s Research and Production Association Energomash will deliver another 20 RD-180 engines to the United States as the first stages for Atlas V carrier rockets, Energomash said on its website on Thursday.

"Until 2019 inclusive, Energomash will deliver another 20 RD-180 engines to the United States for their use as the first stages for the Atlas V carrier rocket," the company said in a statement.

Energomash has signed an additional agreement with the US-based RD Amross to the contract on the delivery of engines, the statement said.

The US-based United Launch Alliance set up by Boeing and Lockheed Martin announced on Wednesday it had ordered 20 additional RD-180 engines.

The US Congress earlier imposed restrictions on the use of these Russian-made engines in the United States. The United Launch Alliance management has said its available stock of RD-180 engines won’t suffice to fulfill all its obligations to commercial customers and simultaneously take part in government tenders in the upcoming three years.