The Russian military is conducting a simulated nuclear attack while the upper house of government revokes its ratification of a treaty banning nuclear testing.

The Russian armed forces carried out a simulated nuclear attack during a drill led by President Vladimir Putin on Wednesday, following a vote by the upper house of parliament to withdraw the country’s ratification of a global nuclear test ban.

The legislation to terminate the ratification process for the Comprehensive Nuclear Test Ban Treaty was passed by the lower chamber last week and will now be submitted to Putin for his ultimate approval. Putin has stated that withdrawing Russia’s ratification from 2000 would be in line with the U.S.’s decision, as they also signed but did not ratify the treaty.

Putin was seen in a video call with high-ranking military officials, directing the exercise, which was broadcasted on state television.

The drills, according to Russia’s Minister of Defense Sergei Shoigu, aim to simulate “responding to a nuclear strike from the enemy with a large-scale nuclear attack from strategic offensive forces.”

Although similar exercises occur annually in the fall, Shoigu’s direct remarks were made during a time of heightened tensions between Russia and Western countries due to the conflict in Ukraine.

The 1996 test ban treaty prohibits nuclear explosions worldwide, but it has not been fully enforced. Apart from the U.S., it still needs ratification from China, India, Pakistan, North Korea, Israel, Iran, and Egypt.

There is a growing worry that Russia may restart nuclear testing as a tactic to dissuade the West from providing military aid to Ukraine. Numerous Russian hardliners have expressed support for resuming the tests.

Putin has acknowledged that there are experts who believe nuclear testing is necessary, but he has not yet formed his own opinion on the matter.

Earlier this month, Deputy Foreign Minister of Russia Sergei Ryabkov stated that Moscow will uphold the ban and will only conduct nuclear tests if the United States does so first.

On Wednesday, Ryabkov announced that the Russian Foreign Ministry had been presented with U.S. suggestions to restart discussions about strategic stability and arms control matters. However, he stated that due to the current political climate, Moscow does not believe this is feasible.

According to Ryabkov, the current hostile policy towards Russia must be changed before a discussion on strategic stability, similar to past ones, can take place. He stated this to reporters through Russian news agencies, stating that they are not prepared for it at this time.