(Reuters) -The European Union should step up sanctions on Russia to target its lucrative energy sector, the foreign ministers of Lithuania and Ireland said in Brussels on Monday.
Trying to force a Russian military withdrawal from Ukraine, the European Union and its Western allies have already imposed a panoply of sanctions including freezing the Russian central bank's assets.
The humanitarian crisis in the port city of Mariupol, where residents are besieged with little food, water, and power, is increasing pressure on European leaders to toughen sanctions on Moscow.
"Looking at the extent of the destruction in Ukraine right now it's very hard to make the case that we shouldn't be moving in on the energy sector, particularly oil and coal," Irish Foreign Minister Simon Coveney said as he arrived at a meeting of EU foreign and defense ministers.
Diplomats told Reuters that Baltic countries including Lithuania are pushing for an embargo as the next logical step, while Germany is warning against acting too quickly because of already high energy prices in Europe.
"It's unavoidable we start talking about the energy sector, and we can definitely talk about oil because it is the biggest revenue to Russia's budget," Lithuanian Foreign Minister Gabrielius Landsbergis said.
"We cannot get tired of imposing sanctions, we cannot get tired of bringing assistance and help to Ukraine," he said.
The credibility of the West was on the line, he said.
U.S. President Joe Biden arrives in Brussels on Thursday for summits with NATO's 30 allies, the EU, and in a Group of Seven (G7) format including Japan, designed to harden the West's response to Moscow.
The Kremlin has so far not been moved to change course in Ukraine by four rounds of EU sanctions imposed over the past three weeks, including on 685 Russians and Belarusians and on Russian finance and trade.
A fifth-round of sanctions will include adding more names to the EU blacklists.
But the economically toughest choice is whether to target Russian oil, as the United States and Britain have done, given the 27-nation EU's dependence on Russian gas for energy.
Russia invaded Ukraine on Feb. 24. Putin has called Russia's actions a "special operation" meant to demilitarize Ukraine and purge it of what he sees as dangerous nationalists.
Ukraine and the West say these are baseless pretexts for an aggressive war.
"A massive war crime is happening in Mariupol," EU foreign policy chief Josep Borrell said. "Russia is doing a lot of war crimes."
FRANCE SAYS 'NO TABOOS' ON SANCTIONS
Diplomats have said a Russian chemical weapons attack in Ukraine, or a heavy bombardment of the capital Kyiv, could be a trigger for an energy embargo.
Moscow itself has warned that EU sanctions on Russian oil could prompt it to close a gas pipeline to Europe.
For now, the EU, which relies on Russia for 40% of its gas, with Germany among the most dependent of the EU's large economies, is divided on how to tackle the energy issue.
France, which heads the EU's six-month presidency, could prove crucial.
President Emmanuel Macron has said that if the situation worsens even further in Ukraine - where thousands have been killed, millions displaced and some cities devastated by shelling - there should be no "taboos" in terms of sanctions.
Defense ministers will also discuss a "strategic compass," a new EU military strategy meant to adapt the bloc to a new geopolitical reality.