Russian officials told IRI that it must halt its work in Russia because it is financed by the US Agency for International Development (USAID), which was forced out of the country earlier this year, IRI spokeswoman Lisa Gates told RIA Novosti.

The Russian government in recent years has tightened its oversight of foreign funding of political groups that are highly critical of Russia’s leaders—measures it calls necessary to prevent outside interference in its political process.

Political opposition groups, meanwhile, say these initiatives are aimed at stifling dissent.

The closing of IRI in Russia comes on the heels of a Russian law enacted in July requiring nongovernmental organizations (NGOs) that receive foreign financing and engage in political activities to register as “foreign agents.”

But Gates said that the organization’s looming exit was precipitated not by the new NGO law, but rather by its funding from USAID, which was ordered by Moscow in September to halt its work in Russia.

“IRI was told by Russian officials it had to leave the country since it was funded by USAID,” Gates said in emailed comments. “It had nothing to do with the NGO law.”

Russian officials have previously accused IRI of meddling in the country’s domestic politics.

The Russian Foreign Ministry could not immediately be reached for comment on Thursday.

USAID spokeswoman Lisa Hibbert-Simpson told RIA Novosti that all of the agency’s programs in Russia had wrapped up as of Oct. 1.

Hibbert-Simpson said she did not have any further information on “what the Russian government communicated to IRI.”

The end of IRI’s activities in Russia was first reported on Thursday by the Foreign Policy website, which cited US Sen. John McCain, who serves as IRI chairman, and is a fierce critic of Russian President Vladimir Putin.

McCain, however, suggested in the report that it was the onerous conditions of the new NGO law that prompted the closure.

“They have to pull out, given the conditions,” McCain was quoted as saying by Foreign Policy. “The Russians said that any organization that operates with US funding is subject to all kinds of restrictions.”

McCain’s office did not respond to requests for comment by telephone and email on Thursday.

The Russian government ordered USAID to shut down its activities in the country in September, accusing the US government agency of meddling in the country’s politics.

“We are talking about issuing grants in an attempt to affect the course of the political process in the country, including elections at different levels and institutions in civil society,” the Russian Foreign Ministry said in a statement at the time.

IRI states on its website that its activities in Russia include supporting “the political and civic development of the country by promoting and supporting engagement between citizens and political actors.”

Gates told RIA Novosti on Thursday that the organization would continue to work “on Russia,” but that it is not sure “from where at this point.”

The circumstances surrounding USAID in Russia has prompted the National Democratic Institute (NDI), another private American NGO eyed with suspicion by Moscow for funding politically active groups, to reconsider aspects of its work in the country.

The organization has moved some of its Russia-based staff to Lithuania “temporarily as we sort out our options,” an NDI spokesperson told RIA Novosti on Thursday.

“In light of the recent departure of USAID and other developments in Russia, NDI is currently assessing ways it can most effectively continue to fulfill its mission,” the organization said in a statement. “The situation is very fluid and we are evaluating options.”

NDI did not respond to a request for comment Thursday afternoon on whether it was being pressured by Russian officials to close its operations in the country due to the funding the Washington-based organization receives from USAID.