Russian prosecutors declared Tuesday that the US National Endowment for Democracy will be the first "undesirable" foreign group banned under a controversial new law designed to limit the influence of overseas organizations perceived as a threat.

"Taking into account the overall aim of the Endowment's work, prosecutors came to the conclusion that it presents a threat to the constitutional order of Russia, its defense capabilities and state security," the prosecutors said in a statement.

The Endowment, the statement continued, "participated in work to declare the results of election campaigns illegitimate, to organize political demonstrations aimed at influencing decisions taken by state institutions and to discredit service in the Russian armed forces."

Critics view the ban as an attempt by Moscow to limit civil society amid growing anti-Western rhetoric over the Ukraine conflict. Endowment officials immediately blasted the ban.

"This law, as well as its predecessors, contravenes Russia's own constitution as well as numerous international laws and treaties," the endowment said in a statement. "The true intent of these laws is to intimidate and isolate Russian citizens."

The Endowment added that it "remains committed to supporting human rights and fundamental freedoms throughout the world."

The Russian justice ministry is expected to approve the measure, which will see the Endowment barred from opening offices in Russia or providing funding to any individuals or groups within the country. In 2013 and 2014, the Endowment provided about $5.2 million (4.7 million euros) in funding to local organizations, according to Russian prosecutors.

The ban comes amid heightened tensions over the Ukraine crisis, which has seen relations between Russia and the West plummet to their worst level since the end of the Cold War.

Earlier this month, Russian senators drew up an official proposal to blacklist 12 foreign non-governmental organizations, including the Endowment. Dozens of organizations, including leading human rights groups have been impacted by the restriction.

Under the new law, activists could face a prison term of up to six years for "participating in the activities" of any banned entity.

bw/lw (AFP, AP, dpa)