On Wednesday night, the US President announced sanctions against Russia’s two largest oil companies, Rosneft and Lukoil. The measures followed the collapse of a proposed meeting with Vladimir Putin.

The Kremlin had signalled it was unwilling to meet America’s terms for a ceasefire.

“The US is our enemy, and its talkative ‘peacemaker’ has now fully embarked on the warpath with Russia,” Mr Medvedev wrote on Telegram. 

“The decisions taken are an act of war against Russia. And now Trump has fully aligned himself with loony Europe,” said the Deputy Chair of Russia’s National Security Council, reigniting his war of words with the US President.

The European Union also announced new sanctions on Russia, including a ban on the import of liquefied natural gas. The natural gas ban will phase out imports rather than halt them immediately.

On Thursday, German Chancellor Friedrich Merz said he was confident European leaders would now move to seize €210 billion (£180 billion) in frozen Russian assets, despite objections from Belgium. 

“I share the Belgian Prime Minister’s concerns but am confident we will take a step forward,” Mr Merz told reporters at an EU summit in Brussels.

The EU also imposed new travel restrictions on Russian diplomats in the Schengen Zone and prohibited another 117 ships in Russia’s shadow fleet, a clandestine armada of tankers that ship oil in breach of Western sanctions, from accessing EU ports.

Mr Trump’s decision to impose sanctions marks the latest shift in his relations with Putin, who has frustrated the President’s desire to capitalise on the ceasefire in Gaza with a deal in Ukraine. 

“Look, these are tremendous sanctions,” Mr Trump told reporters in the Oval Office. “These are very big ones that are against their two big oil companies, and we hope that they won’t be on for long. We hope that the war will be settled.”

He added that the sanctions were designed to push Putin back to the negotiating table.

“Hopefully he’ll become reasonable, and hopefully Zelensky will be reasonable,” he said. “You know, it takes two to tango, as I say, and we’ll find out.”

The initial measures on Russian oil are unlikely to make much difference to Russia’s economy. However, oil prices jumped by almost 3% (more than $2 per barrel) following the announcement, which also included a threat to impose ‘secondary’ sanctions on foreign buyers of Russian oil.

The sanctions mean that any Russian assets held by the companies in the US will be frozen. Banks or people who deal with the two oil companies and their subsidiaries could also face sanctions.

Mark Rutte, the head of Nato, said the move was about “changing the calculus” by putting more pressure on the Kremlin.

He joined Mr Trump in the White House after flying to Washington to deliver a 12-point peace plan drawn up by Europe.

Volodymyr Zelensky, Ukraine’s President, hailed the US’s and EU’s measures as he arrived for a summit of European leaders in Brussels to discuss support for his war-torn country.

Ahead of the talks, Belgium threatened to derail plans for a €140 billion loan using frozen Russian assets to fund Ukraine’s war efforts for the next three years.

Its Prime Minister, Bart de Wever, said he would “do everything” in his power to block the planned loan unless the EU’s member states agree to share the burden of any financial risk. …

In the Oval Office on Wednesday, Mr Trump confirmed the summit [with Putin] had been cancelled.

“Every time I speak with Vladimir, I have good conversations, and then they don’t go anywhere. They just don’t go anywhere,” Mr Trump said. “It’s time to make a deal. A lot of people are dying.”