Morawiecki met with Dutch Prime Minister Mark Rutte on Monday to discuss further actions European countries could take to punish Russia, including a ban on all oil and gas imports.

“We talked today about a blockade of all European ports to Russian ships and also on all sorts of sanctions, including on oil and gas,” Morawiecki said in a statement, according to Ahram Online. Morawiecki also said the leaders vowed to punish Russia for committing “terrible, cruel crimes” against Ukrainians during the war.

On Monday, Dmitry Medvedev, Russia’s former president and current deputy chairman of the Russian security council, wrote a lengthy letter denouncing Poland’s actions. Medvedev sharply criticized Poland for siding with the U.S. and other Western nations to punish Russia, and he warned that Poland’s decisions have caused significant economic suffering.

“The interests of the citizens of Poland have been sacrificed due to Russophobia of ‘mediocre politicians’ and their ‘puppeteers from across the ocean’ with clear signs of senile insanity,” Medvedev wrote in a post on his Telegram channel.

“Morawiecki solemnly announced the development of a program for ‘de-Russification of the Polish and European economy.’ Courageously specifying that ’this may be costly,’” Medvedev wrote. “It’s absolutely and completely right that it is expensive and thoughtless.”

Medvedev added that Poland, and Polish propaganda, is “the most vicious, vulgar and shrill critic of Russia. Community of political idiots.”

Poland has been one of Russia’s toughest European critics and has previously joined the Baltic States in calling for the European Union (EU) to issue further sanctions on Moscow. However, Morawiecki’s call for a full blockade on trade with Russia has prompted other EU leaders to dismiss the idea as unrealistic.

The EU imports nearly a third of its oil from Russia and has so far hesitated to join the U.S. and U.K. in issuing a full embargo. Some nations, including Germany, have warned that a ban on oil and gas could result in widespread unemployment and poverty, The Guardian reported.

However, the EU is set to further discuss an oil embargo and a number of other proposed sanctions this week when U.S. President Joe Biden visits Brussels for talks with NATO and European allies. During that visit, White House Press Secretary Jen Psaki said Biden will make a stop in Poland.

Poland has received more Ukrainian refugees than any other European country since the start of Russia’s invasion on February 24. According to the United Nations, nearly 10 million Ukrainians have been forced to flee their homes, including 3.4 million who have sought refuge abroad.

For the latest updates on the Russia-Ukraine war, visit Newsweek’s live blog.