The Post's Devlin Barrett explains why Moscow-headquartered RT, formerly Russia Today, has conceded after a months-long battle with the U.S. Justice Department. (Sarah Parnass/The Washington Post)

RT, a Moscow-headquartered website and television channel that the U.S. government says is a propaganda outlet for the Kremlin, will register with U.S. authorities as a foreign agent, its editor said Thursday.

The registration follows a months-long back-and-forth between RT and the Justice Department over whether it was required by U.S. law to register as an agent of the Russian government.

“The American Justice Department has left us with no choice,’’ RT’s editor in chief Margarita Simonyan said in a statement posted on the organization’s website. “Our lawyers say that if we don’t register as a foreign agent, the director of our company in America could be arrested, and the accounts of the company could be seized. In short, in this situation the company would not be able to work. Between those consequences and registering as a foreign agent, we are forced to choose registration.’’

She added: “We will continue to work and continue to fight this as long as it’s possible.’’

Formerly known as Russia Today, RT disputes that it is an agent of the Russian government, arguing that it offers alternatives to mainstream news coverage. U.S. intelligence agencies have concluded that the network and website push relentlessly anti-American propaganda at the behest of the Russian government.

Russian state-owned television station RT logo is seen at the window of the company's office in Moscow on Oct. 27, 2017. (Pavel Golovkin/AP)

The Russian Embassy in Washington suggested Thursday that U.S.-based news organizations with reporters in Moscow could face retaliation. In a statement, the embassy said RT was given “an ultimatum to register as a foreign agent by Nov. 13’’ and if the company doesn’t comply, the U.S. government is “threatening to start arresting staff’’ and freezing bank accounts.

The embassy warned that restrictions on the activities of Russian media “would inevitably entail immediate and reciprocal measures.’’

Russian President Vladi­mir Putin was asked about the controversy at a foreign policy event last month. In response to a question from Simonyan, Putin said, “As soon as we see any efforts to limit our mass media, we will reciprocate immediately.”

Russian news media reported in October that the upper house of the Russian parliament had drawn up a blacklist of at least five U.S. media outlets whose activities in Russia could be restricted in response.

A Justice Department spokesman declined to comment.

A January assessment by U.S. intelligence agencies described RT America TV as “a Kremlin-financed channel operated from within the United States, (which) has substantially expanded its repertoire of programming that highlights criticism of alleged US shortcomings in democracy and civil liberties.’’

The assessment also said RT America “has positioned itself as a domestic US channel and has deliberately sought to obscure any legal ties to the Russian government,’’ but behind the scenes, “The Kremlin staffs RT and closely supervises RT’s coverage, recruiting people who can convey Russian strategic messaging because of their ideological beliefs.’’

The Foreign Agents Registration Act (FARA), passed in the run-up to World War II as a means of exposing pro-Nazi propagandists in the United States, requires that Americans working on behalf of foreign governments register as such with the government.

The requirements are enforced by the Justice Department, but some critics, including the head of the Senate Judiciary Committee, Sen. Charles E. Grassley (R-Iowa), have said the department has a poor track record of making firms and individuals follow the law.

The issue of Russian propaganda in the United States has become a hot topic in the wake of the 2016 presidential election, as lawmakers and intelligence officials have pointed to thousands of social media accounts directed from Russia that posed as Americans voicing their opinions on domestic political issues. U.S. intelligence agencies have concluded that Russia sought to interfere with the U.S. election to help Donald Trump get elected.

As RT’s work has come under greater scrutiny from the Justice Department, the company has accused the United States of trying to infringe on the rights of a free press. Other foreign news organizations operating in the United States have filed under FARA with little observable impact on their business.