Bulgaria has joined Slovakia, Hungary and the Czech Republic in seeking to be exempt from a ban on Russian oil imports, diplomatic sources told dpa, after the European Commission unveiled the plans on Wednesday.
Representatives from the 27 EU member states examined the proposals - a further punishment for Russia for its invasion of Ukraine - in Brussels on Wednesday.
"Let us be clear, it will not be easy. Some member states are strongly dependent on Russian oil. But we simply have to work on it," EU Commission President Ursula von der Leyen told the European Parliament in Strasbourg.
The new sanctions package, the sixth since the invasion began on February 24, will requires unanimity across the member states for it to be adopted.
Von der Leyen's proposal would see Russian crude oil banned from the bloc within six months and for refined products to be phased out before the end of the year.
The timeline follows weeks of negotiations to deprive Russia of a significant revenue stream, in a move that would also have a significant economic fallout in Europe.
The plan gained momentum after Germany, a huge importer of Russian energy, announced it would support a ban.
Hungary has opposed EU moves to target Russian energy imports with sanctions throughout the Ukraine war and repeated reservations about the commission's oil embargo proposal.
"We do not see any plans or guarantees on how a transition [to alternative sources] could be managed based on the current proposals," government spokesman Zoltan Kovacs said on Twitter.
How Hungary's energy security would be guaranteed under the proposed sanctions was also unclear, Kovacs added. Hungary, like Slovakia, has struggled to source new oil supplies due to lack of sea access and is heavily dependent on Russian oil imports.
Czech Prime Minister Petr Fiala called for his country to be allowed to delay implementing any oil ban for two to three years so that it could develop alternative pipeline routes.
European Commission Vice President Maroš Šefčovič said however he was confident that there would be agreement on the new sanctions.
Šefčovič also announced plans for new measures to tackle rising energy prices in the EU as a result of the Ukraine war by the end of the month.
In other measures, Von der Leyen announced the expulsion of Sberbank, Russia's largest bank, from the international financial communication system, SWIFT.
The top EU official said two other Russian banks are to be expelled so as "to solidify the complete isolation of the Russian financial sector from the global system," after previous EU sanctions hit the Russian central bank and other financial institutions.
In addition, Russian military officials involved in atrocities in Ukraine's Bucha and Mariupol are to be hit with sanctions, von der Leyen said.
"This sends another important signal to all perpetrators of the Kremlin's war: We know who you are, and you will be held accountable," von der Leyen said.
The bloc is to target three more Russian state-owned broadcasters in the new sanctions, von der Leyen said. Accountancy services and public relations companies are to also be barred from doing business in Russia.
"We have identified these TV channels as mouthpieces, that amplify Putin's lies and propaganda aggressively," von der Leyen told the European Parliament, referring to the Russian president.
"The Kremlin relies on accountants, consultants and spin-doctors from Europe. And this will now stop," she said.
The head of the Russian Orthodox Church, Patriarch Kirill, a supporter of Russian President Vladimir Putin, is also targeted, according to diplomatic sources, however von der Leyen did not announce this.
The top EU official also called for an "ambitious recovery package" for Ukraine and for further economic support to help the country weather the economic impact of the Russian invasion.
Representatives for the 27 EU member states are to continue examining the proposals with a deadline for submitting amendments set for Thursday at midday.
US President Joe Biden said meanwhile that he would consider imposing more sanctions on Russia for its invasion of Ukraine.
"We're always open to additional sanctions. And I've been in consultation. I'll be speaking with the members of the G7 this week about what we're going to do or not do," he said in Washington.
