The United States has unveiled a new round of punitive sanctions against Moscow for its appropriation of Crimea, targeting several close associates of President Vladimir Putin, including his chief of staff and his personal banker, and served notice that Russia’s key oil and energy sectors would be targeted next if it goes any further into Ukraine.

The move by President Barack Obama came as talks among European officials in Brussels were expected to go well into the night. Around a dozen Russian names will likely to be added to the 21 Ukrainian and Russian officials put under travel bans and assets freezes by EU foreign ministers on Monday.

Outlined by Mr Obama in a sober appearance on the White House South Lawn, the new measures were meant to demonstrate he was serious when he said at the start of the crisis that “costs” would be imposed on Russia for its actions.

Download the new Independent Premium app Sharing the full story, not just the headlines

Even as the new US measures will penetrate further than ever into Mr Putin’s inner circle of associates and advisors, potentially far more impactful was the authority also signed by Mr Obama yesterday for the US government to impose additional sanctions against vital areas of the Russian economy if Moscow attempts any further incursions into Ukraine territory. They could span the financial services sector and the energy, defence and mining sectors.

“This is not our preferred outcome,” Mr Obama said in a brief statement. “These sanctions would not only have a significant impact on the Russian economy, but could also be disruptive to the global economy. However, Russia must know that further escalation will only isolate it further from the international community.”

Earlier this week, the US froze the US-based assets of 11 Russian and Ukrainian figures and barred them from all dollar transactions. Mr Obama added 20 more to the list yesterday, many of them senior figures either close to or inside the Kremlin. They included Sergei Ivanov, Mr Putin’s chief of staff, as well as Arkady Rotenberg and Gennady Timchenko, both lifelong Putin friends who have earned fortunes through government contracts.

But also on the list was St Petersburg-based Bank Rossiya, which, according to US officials has served as the first bank of choice to man top Kremlin officials. It is owned by Yuri Kovalchuck, also a friend of President Putin and sometimes described as his personal banker. The bank will be “frozen out of the dollar”, one US official stated.

Shape Created with Sketch. Crimea referendum and independence Show all 14 left Created with Sketch. right Created with Sketch. Shape Created with Sketch. Crimea referendum and independence 1/14 Crimea Referendum A man shows his shirt with the Russian emblem as he celebrates the results of the Crimean referendum at the Lenin Square in Simferopol EPA 2/14 Crimea Referendum An elderly retired Soviet Navy officer and his wife take a walk in Sevastopol the morning after the referendum AFP/Getty 3/14 Crimea Referendum A man plays accordion as people dance during celebrations in Sevastopol AFP 4/14 Crimea Referendum People wave Russian flags as fireworks explode in the sky over Sevastopol following the announcement of the result of the referendum EPA 5/14 Crimea Referendum A member of a Ukrainian "Maidan" self-defense battalion takes part in training to qualify for service in the newly-created National Guard. Reuters 6/14 Crimea Referendum Pro-Russian protesters hold a Russian, Crimean and Soviet flags during their rally at Lenin Square in Simferopol, Ukraine EPA 7/14 Crimea Referendum A member of the Crimean election commission waits for voters at the polling station in Belogorsk near Simferopol, Crimea, Ukraine EPA 8/14 Crimea Referendum Polling stations opened in Crimea for a referendum about whether the Ukrainian Black Sea region should join Russia. The vote has been widely condemned by Western governments, who call it illegal and have announced sanctions against Russia if it goes ahead. Thousands of unmarked forces, believed to be Russian, have appeared in Crimea after local Moscow-backed authorities asked Russia for protection against 'extremists' in the new Ukrainian leadership EPA 9/14 Crimea Referendum A lettering on the facade of the Council of Ministers building reads 'Spring in Crimea' in Simferopol, Crimea, Ukraine EPA 10/14 Crimea Referendum People wave Crimean flags at Lenin square in Simferopol, Crimea, Ukraine EPA 11/14 Crimea Referendum A poster in Crimea presents a stark choice - Nazism, or Russia - to voters ahead of the referendum 12/14 Crimea Referendum Protesters against Ukraine’s referendum gather in Simferopol Getty Images 13/14 Crimea Referendum Action stations: Preparations for today’s referendum in Simferopol, where Crimea will vote to become part of Russia AP 14/14 Crimea Referendum Cossacks guard the regional parliament building in Simferopol during the Crimean referendum AP 1/14 Crimea Referendum A man shows his shirt with the Russian emblem as he celebrates the results of the Crimean referendum at the Lenin Square in Simferopol EPA 2/14 Crimea Referendum An elderly retired Soviet Navy officer and his wife take a walk in Sevastopol the morning after the referendum AFP/Getty 3/14 Crimea Referendum A man plays accordion as people dance during celebrations in Sevastopol AFP 4/14 Crimea Referendum People wave Russian flags as fireworks explode in the sky over Sevastopol following the announcement of the result of the referendum EPA 5/14 Crimea Referendum A member of a Ukrainian "Maidan" self-defense battalion takes part in training to qualify for service in the newly-created National Guard. Reuters 6/14 Crimea Referendum Pro-Russian protesters hold a Russian, Crimean and Soviet flags during their rally at Lenin Square in Simferopol, Ukraine EPA 7/14 Crimea Referendum A member of the Crimean election commission waits for voters at the polling station in Belogorsk near Simferopol, Crimea, Ukraine EPA 8/14 Crimea Referendum Polling stations opened in Crimea for a referendum about whether the Ukrainian Black Sea region should join Russia. The vote has been widely condemned by Western governments, who call it illegal and have announced sanctions against Russia if it goes ahead. Thousands of unmarked forces, believed to be Russian, have appeared in Crimea after local Moscow-backed authorities asked Russia for protection against 'extremists' in the new Ukrainian leadership EPA 9/14 Crimea Referendum A lettering on the facade of the Council of Ministers building reads 'Spring in Crimea' in Simferopol, Crimea, Ukraine EPA 10/14 Crimea Referendum People wave Crimean flags at Lenin square in Simferopol, Crimea, Ukraine EPA 11/14 Crimea Referendum A poster in Crimea presents a stark choice - Nazism, or Russia - to voters ahead of the referendum 12/14 Crimea Referendum Protesters against Ukraine’s referendum gather in Simferopol Getty Images 13/14 Crimea Referendum Action stations: Preparations for today’s referendum in Simferopol, where Crimea will vote to become part of Russia AP 14/14 Crimea Referendum Cossacks guard the regional parliament building in Simferopol during the Crimean referendum AP

Moscow swiftly struck back last night announcing entry bans into Russia on 9 senior US figures, including John Boehner, the speaker of the House, and some top foreign policy aides to Mr Obama. On Capitol Hill, the office of the speaker said he was “proud to be included on a list of those willing to stand against Putin's aggression”.

While the White House is under no illusions about ever setting Crimea free of Russia, it is adamant that the steps it has taken and might take will cause Moscow pain. “Sanctions build over time. They are very powerful. And people may think that they are a mere wrist slap. I can assure them that they are not,” the official said.

It is particularly alarmed at a build-up of Russian troops that could spell further aggression against Ukraine. “The world is watching with grave concern as Russia has positioned its military in a way that could lead to further incursions into southern and eastern Ukraine,” said Mr Obama. Next week will travel to The Hague to preside over specially convened meeting of the Group of Seven leading industrial nations, with the usual eighth chair at the table for Russia taken away.

Daily coronavirus briefing No hype, just the advice and analysis you need Enter your email address Continue Continue Please enter an email address Email address is invalid Fill out this field Email address is invalid Email already exists. Log in to update your newsletter preferences Register with your social account or click here to log in I would like to receive morning headlines Monday - Friday plus breaking news alerts by email Update newsletter preferences

European leaders were struggling to find common ground between the more hawkish states that want to hit Russia with the most punishing economic sanctions available, and those who fear the fallout for Europe's struggling economies.

Poland and the Baltic states, wary of their proximity to Russia and with memories of their own Soviet pasts, want to hit Russia as hard as possible with measures such as an arms embargo and bans on gas imports. Nations like Germany, France and Spain with closer business and trade ties are more wary, as are many Eastern European nations which rely on Russia for their energy supplies.

A British official said the aim was “to deter any further Russian action to destabilise Ukraine”, and said they hoped the outcome would include a strong political signal to Russia, possible trade restrictions on goods from Crimea, and an expansion of assets freezes and travel bans. The EU is not, however, expected to go as far as the US and include oligarchs on its list, leaving it open to accusations of weakness.

The Russian opposition politician Alexei Navalny, currently under house arrest, wrote in a New York Times opinion piece that the timidity of the first round of sanctions “is mocked by Russia and even seen as tacit encouragement to Mr Putin and his entourage”. He urged the West to go after powerful oligarchs including the head of state energy firms Gazprom and Rosneft, and Premier League football club owners Roman Abramovich and Alisher Usmanov. This, he said, would deliver “a serious blow to the luxurious lifestyles enjoyed by the Kremlin’s cronies”.

Such moves for now appear a step too far for the EU, as are more serious economic sanctions, although there may be language in the final conclusions again spelling out they remain on the table should Russia make any further moves on Ukrainian territory.

The EU has pulled out what was to have been a G8 summit in Sochi in June. "So long as there aren't the political circumstances, like now, for an important format like the G8, then there is no G8,” the German Chancellor Angela Merkel said.