The Kremlin vowed to further restrict Western media in Russia on Wednesday after the EU's top court upheld European sanctions that took Moscow's RT channel off-air around the continent.

The European Court of Justice (ECJ) in Luxembourg threw out an appeal from state-owned RT France against a broadcast ban which was introduced as part of EU sanctions following Russia's invasion of Ukraine in February.

Finding that the channel "actively supported" Moscow's destabilisation of Ukraine and broadcast pro-war propaganda, the court concluded that the EU's decision was legal and proportionate.

"In the light of those considerations, the general court dismisses the action in its entirety," the judges ruled, referring to RT France's bid to overturn the ban and restrictions on its website.

The channel immediately announced an appeal, while the Kremlin said it would take retaliatory measures.

"Of course, we will take similar measures of pressure on Western media that operate in our country," Kremlin spokesman Dmitry Peskov told reporters in Moscow.

"We will also not let them work in our country," he said, describing the Kremlin's reaction to the ban as "extremely negative."

"Essentially, RT has been blocked and cannot operate in Europe," Peskov said. "Europeans are trampling on their own ideals."

Most Western media outlets are off-air in Russia and have seen their websites banned, while many foreign journalists have left because of draconian new laws that muzzle independent reporters.

Launched in 2005 as Russia Today, RT has grown its reach through broadcasts and websites in several languages including English, French, Spanish, German and Arabic.

The EU's decision to ban RT as well as fellow Kremlin-funded news service Sputnik raised questions about freedom of expression in the 27-member bloc and formed part of RT France's legal appeal.

The Kremlin promised to ban Western media outlets from Russia in retaliation.
The Kremlin promised to ban Western media outlets from Russia in retaliation. AFP / Lionel BONAVENTURE

France's national journalists' union, the SNJ, issued a statement at the end of February calling the targeting of Russian media "an act of censorship."

But the ECJ judges noted that the sanction was temporary -- until July 2022 -- and found that it was "appropriate and necessary to the aims pursued" given the "extraordinary context".

"RT France actively supported... the policy of destabilisation and aggression conducted by the Russian Federation towards Ukraine, which ultimately resulted in a large-scale military offensive," the court's statement said.

Secondly "RT France broadcast, in particular, information justifying the military aggression against Ukraine, capable of constituting a significant and direct threat to the Union's public order and security," it continued.

Evidence presented to the court by RT France was "not capable of demonstrating an overall balanced treatment by the latter of information concerning the ongoing war," the judges concluded.

The channel is seen by critics as parroting Russian state propaganda and has been blocked in most Western countries since President Vladimir Putin sent troops into Ukraine.

Most Western broadcasters in Russia were dropped by their local Russian providers after the invasion and websites including the BBC, France's RFI or Germany's Deutsche Welle are blocked.

Earlier this month, Russian President Vladimir Putin signed a decree that gave the government powers to shut media organisations from countries that were considered "unfriendly."

Western social networks such as Facebook, Twitter and Instagram are also banned.

The censors can be circumvented by using a VPN which hides the location of a computer as it accesses the internet.

Elsewhere on Wednesday, Russian energy giant Gazprom drastically cut gas deliveries to Europe via the Nord Stream pipeline to about 20 percent of its capacity, German authorities said.