GDAŃSK, Poland — The European Union’s plans to impose hefty restrictions on Russian banks and energy companies will face major hurdles as the bloc’s most Kremlin-friendly countries threaten to wield their right of veto.

Slovakia’s populist Prime Minister Robert Fico said on Wednesday that he would not support efforts to target the revenues Russia is using to fund its war in Ukraine, “unless the European Commission provides it with a realistic solution to the crisis situation Slovakia will find itself in after the full stoppage of gas, oil and nuclear fuel supplies from Russia.”

Hungary’s hard-right leader, Viktor Orbán, has also repeatedly threatened to block additional EU sanctions on Russian energy, which require the unanimous approval of all 27 member countries.

In addition to imposing restrictions on Russian banks, the new package of measures — the 18th to be imposed since the start of the full-scale war — would hit firms linked to the Nord Stream pipelines, and commit Brussels to a ban on imports of fuel refined from Russian oil by third countries.

European Commission President Ursula von der Leyen unveiled the proposals on Tuesday, also committing to supporting a reduction in the $60-per-barrel oil price cap at a meeting of G7 leaders in Canada this weekend.

Poland, which holds the rotating presidency of the Council of the European Union, has expressed hopes of passing the package into law before it hands over the role to Denmark on July 1, meaning capitals would have to negotiate an agreement likely before a meeting of leaders on June 27.

“We will work at full speed to have the new sanctions adopted still under the Polish presidency,” said Ignacy Niemczycki, the country’s secretary of state for Europe.

Behind closed doors

Ambassadors met on Tuesday evening in Brussels to discuss the proposals. “The reaction was not as negative behind closed doors,” said one diplomat, granted anonymity to speak about the sensitive discussions. “We will have to see what Hungary and Slovakia want but there’s a deal that can be made.”

The EU has to simultaneously secure support for a new roadmap on eliminating Russian energy, which introduces a 2027 deadline for the phaseout of all gas imports. Detailed legal proposals are expected to be unveiled on June 17, but Budapest and Bratislava have called for exemptions.

Two EU diplomats told POLITICO the European Commission was taking a tougher and more uncompromising approach to this round of sanctions. While it would normally avoid suggesting ideas that would lead to a veto, this time the EU executive appears to be less concerned.

At least von der Leyen can fly into the G7 summit in Alberta, Canada, on the back of a big sanctions announcement — putting the ball in Washington’s court to raise the pressure on Russian President Vladimir Putin to come to the negotiating table and make peace with Ukraine.

So far, however, U.S. President Donald Trump has shown little interest in a proposal pitched by Republican Senator Lindsey Graham to hit countries that buy energy from Russia with a 500 percent tariff.

“It’s definitely different,” one of them said of the latest Commission proposal. “They are ambitious and are also saying what they want to do [in a press conference]. If there’s no deal, von der Leyen risks looking weak.”

The crunch is likely to come later this month, in the countdown to an EU leaders’ summit in Brussels on June 26-27.

The second diplomat assured the Commission “wouldn’t propose if they don’t see options” for the package to be adopted. They were unfazed by Fico’s threats. “We have 17 packages and don’t see any reason why we can’t get another one.”

Both diplomats expected a deal is possible, because behind closed doors Hungary and Slovakia were not as vocal as in public.

Gabriel Gavin reported from Gdańsk. Koen Verhelst reported from Brussels.