MOSCOW — A nonprofit group that promotes democracy has become the latest American-linked group to be banned in Russia under restrictions on “undesirable” organizations signed into law by President Vladimir V. Putin in May.

The office of Russia’s prosecutor general on Thursday outlawed the group, the National Democratic Institute, claiming in a statement that the it posed “a threat to the foundations of Russia’s constitutional order and national security.”

The restrictions on so-called undesirable organizations are meant to limit the influence of outside groups in Russia and to prevent what the Kremlin worried might be a foreign-sponsored uprising against the government.

Russians are barred from working with organizations deemed to fall under the law, and the offices of such groups in Russia have been shut and their assets frozen. With the National Democratic Institute, five organizations have now been added to the list, all American-linked. They include the nonprofit National Endowment for Democracy, and the Open Society Foundations, a group founded by the billionaire George Soros to help countries make the transition from Communism. The MacArthur Foundation, which is based in Chicago and which awards grants for activities related to higher education, human rights and limiting the proliferation of nuclear weapons, closed its offices in Russia in July.