Members of the Collective Security Treaty Organization (CSTO) military alliance called on the U.S. Thursday to renew the Strategic Arms Reduction Treaty (START) with Russia.

In a joint statement issued in Kyrgyzstan’s capital Bishkek following a meeting, the heads of the six CSTO member states of Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia and Tajikistan said they were “concerned over the worsening international security situation and weakening of the legal mechanisms for its maintenance.”

“We regret the termination of the Intermediate-Range Nuclear Forces Treaty and are deeply concerned about the future of the Strategic Arms Reduction Treaty, which expires in February 2021.

Read more: CSTO asks US to renew arms reduction treaty with Russia