The growing tension between Russia and the United States over cruise missiles and the daring patrols of Russian nuclear submarines is threatening to bring back the arms rivalry between two of the world’s most dominant nuclear forces. The U.S. has warned it will take action in retaliation for the new cruise missile Russia had recently developed.

In 2014, the Federation of American Scientists has noted that the number of strategic nuclear warheads deployed by Russia and the U.S. have increased with both nations spending billions of dollars every year to upgrade their military arsenals. Amid the Ukraine conflict and Russia’s sinking economy, Russian President Vladimir Putin is putting more emphasis on his country’s nuclear weapons as symbols of great influence. He has earlier warned other countries in a speech last summer that they should not “mess” with Russia.

Meanwhile, Russia’s attack robots are being prepared for testing in the Astrakhan region before they are deployed to the country’s Strategic Missile Forces. The Moscow Times reported that the trials will focus on the exploration of mobile and stationary robotic systems including technology responsible for signaling and stealth.

Major Dmitry Andreyev from the Defence Ministry’s Strategic Missile Forces declared that the preparation for the attack robot trials is on its final stage. The testing is part of Russia’s plan to deploy robots to protect its intercontinental ballistic missile launch sites by 2020. Andreyev had described the robots of having a remote-controlled firing system.