US Secretary of State Antony Blinken has announced new sanctions against the Russian media channel RT, accusing it of being a "de facto arm of Russia's intelligence apparatus".

The top US diplomat told reporters on Friday that RT is part of a network of Russian-backed media outlets which have sought to covertly "undermine democracy in the United States".

He added that the Russian government has "embedded within RT, a unit with cyber operational capabilities and ties to Russian intelligence".

RT live-streamed Mr Blinken's remarks on X and declared it the "US's latest conspiracy theory".

Foreign ministry spokeswoman Maria Zakharova said there should be a "new profession" in the US, of specialist in sanctions imposed on Russia.

Responding to US allegations that RT had sought to influence elections, RT’s editor-in-chief Margarita Simonyan who was sanctioned by the US last week said they were excellent teachers, adding that many RT staff had studied in the US, and with US funding.

The State Department accused the state broadcaster, formerly Russia Today, of engaging in "information operations, covert influence, and military procurement" in countries in Europe, Africa, and North and South America.

Mr Blinken also accused RT of running online fundraisers to purchase body armour, sniper rifles, drones and other equipment for Russian soldiers fighting in Ukraine.

The network, he said, has also sought to influence Moldova's politics in coordination with Russian intelligence ahead of presidential elections in October 2024.

The US had already indicted two RT employees for allegedly attempting to interfere in this year's presidential election, but US officials said on Friday the state broadcaster played a bigger role in Russia's efforts to undermine democracies.

The state-funded media organisation responded at the time by mocking the US government's accusations, saying in a statement to the BBC that "2016 called and it wants its clichés back".

"Three things are certain in life: death, taxes and RT's interference in the US elections."

Mr Blinken said in a press conference: "Our most powerful antidote to Russia's lies is the truth. It's shining a bright light on what the Kremlin is trying to do under the cover of darkness."

Mr Blinken emphasised that the sanctions were not related to the content of the outlet's reporting, and he affirmed the US's support for independent journalism.

"Covert influence activities are not journalism," he said.

The announcement is part of a suite of actions the US government has taken against Russian state media as the 2024 election approaches. The State Department has also designated RT as a foreign mission.