Russia has formally moved to restrict the activities of Pacific Environment, labeling the longtime U.S.-based environmental and advocacy group an “undesirable organization.”

The group is the latest in a growing number of nongovernmental organizations to be blacklisted by the Justice Ministry, which announced the move on August 28.

It followed a decision last week by the Prosecutor-General’s Office to seek the designation, which said Pacific Environment posed "a threat to the constitutional foundations of Russia and state security."

The San Francisco-based organization has worked in Russia’s Siberia, Far East, and Arctic regions for years, helping to fund local groups and raise awareness of issues like endangered species in Primorsky Krai, oil pollution on Sakhalin, and other matters. It also advocates in other Pacific Rim countries.

The group did not immediately respond to a call and an e-mail seeking comment.

The group is the 15th organization to be blacklisted under the law adopted in 2015 but the first environmental group to be placed on the "undesirables" list.

The blacklist has so far targeted mainly U.S. democracy-promoting organizations, such as the National Endowment for Democracy, or groups funded by figures like U.S billionaire George Soros and exiled Russian oil tycoon Mikhail Khodorkovsky.

The crackdown on foreign organizations followed a separate law passed three years earlier known as the "foreign agents" law. That was aimed at restricting “organizations performing the function of foreign agents” -- which meant Russian nongovernmental organizations that receive foreign funding and conduct “political activities."

Dozens of Russian organizations have been labeled "foreign agents," a designation that requires lengthy, often onerous reporting requirements.