Lithuania is suspending all imports of Russian oil, natural gas and power, the country’s energy minister Dainius Kreivys announced in a statement Sunday, making it the only country in the European Union to suspend all imports on Russian energy.

Lithuania is now receiving liquified gas from the U.S. after becoming the first EU country to suspend Russian gas imports in April, Kreivys said. The country is now generating electricity via local power generation and local EU imports via existing connections with Sweden, Poland and Latvia.

It is unclear what alternate source of oil Lithuania will rely on, but Kreivys’ statement indicates that its sole importer of oil, Orlen Lietuva, refused to import Russian oil more than a month ago, Kreivys said.

The move is an expression of solidarity with Ukraine, Kreivys said, adding that it cannot allow its money to finance a Russian war machine.

The EU stated stated in March that it would end its dependency on fossil fuels imports from Russia and made plans to phase out Russian oil, gas and coal. The European Commission presented details on how it plans to achieve that last week.

-ABC News' Christine Theodorou

While Ukraine has rarely reported on its combat losses since the Russian invasion began in late February, President Volodymyr Zelenskyy announced during a press briefing Sunday that 50 to 100 Ukrainian soldiers are being killed every day.

The last time Zelenskyy revealed military death toll figures was in April, when he said that around 3,000 Ukrainian soldiers had been killed in action and around 10,000 wounded. Zelenskyy did not provide a total figure for combatants killed in action on Sunday.

Since the start of the invasion, most Ukrainian men ages 18 to 60 have been banned from leaving the country. On Friday, a petition calling for the government to cancel the ban was registered with the president’s office.

The petition surpassed the 25,000-signature threshold that requires the president to address it on Sunday. Zelenskyy acknowledged the petition during Sunday's briefing.

"How would I explain that to relatives of our defenders who are fighting at the most difficult positions in the East, where 50 to 100 troops lose their lives every day?"

Ukraines parliament voted to extend martial law through Aug. 23. Zelenskyy’s office has a few weeks to consider the petition.

-ABC News' Christine Theodorou

Ukrainian President Volodymyr Zelenskyy extended a warm welcome to Polish President Andrzej Duda on Sunday amid his bid to have his country join the European Union.

During a parliamentary session, Zelenskyy expressed his gratitude to all Poles for their support, making it clear that pushing full steam ahead to ensure Ukraine is granted candidate status.

"I am sure that all the necessary decisions will be made first for the status of a candidate for Ukraine, and then for full membership," he said. "In particular, thanks to Poland's many years of protection of Ukrainian interests on the European continent."

Shortly after Zelenskyy and Duda addressed lawmakers, the parliament session was briefly interrupted when air sirens sounded in Kyiv, and members of parliament were moved to a shelter. The Ukrainian regional military administration later confirmed a Russian missile was intercepted over the Kyiv region.

France's Minister for European Affairs Clément Beaune in his interview with France TF1 radio said on Sunday that it could take 15 to 20 years for Ukraine to become an EU member state, adding that Kyiv could enter the European political community proposed by French President Emmanuel Macron in the meantime.

-ABC News' Christine Theodorou

The Russian Defense Ministry provided updates to what it described as the “special military operation in Ukraine” on Sunday, saying that hundreds of Ukrainians were killed in recent attacks.

High-precision air missiles and other attacks launched in Donetsk, Lugansk and Krasnyi on Sunday hit command posts, areas where Ukrainian manpower and military equipment are concentrated and ammunition depots, according to the Russian Defense Ministry.

The attacks killed more than 210 Ukrainian nationals and destroyed as many as 38 armored motor vehicles, the ministry claimed.

Russian air defense also shot down 11 Ukrainian aircraft and intercepted “multiple launch rockets” in the Kharkov region, according to the defense ministry.

The ministry claimed that, in total, 174 Ukrainian aircraft and 125 helicopters, 977 unmanned aerial vehicles, 317 anti-aircraft missile systems, 3,198 tanks and other armored combat vehicles, 408 multiple launch rocket systems, 1,622 field artillery and mortars and 3,077 units of special military vehicles were destroyed during the operation.

Jalina Porter, the State Department's deputy spokesperson, is responding to the Russian attack at a Ukraine train station that killed at least 50, saying, "We can no longer be surprised by the Kremlin's repugnant disregard for human life."

Five children were among those killed when Russian rockets struck the station in Kramatorsk in Donetsk Oblast on Friday morning, according to Ukraine's state-owned railway company. At least 100 people were injured, according to Donetsk Oblast Gov. Pavlo Kyrylenko.

Russia has denied involvement in the attack, which occurred as "thousands" of civilians fleeing the Russian invasion were at the train station waiting to be taken to "safer regions of Ukraine," according to Kyrylenko.

"Civilians are killed when they stay in their homes, and they're killed when they try to leave," Porter said. "Actions like these demonstrate why Russia did not belong on the U.N. Human Rights Council, and they also reinforce the U.S. assessment that members of Russian forces are committing war crimes in Ukraine."

Porter declined to say if the department considers the train station attack a war crime, saying, "Assessing individual criminal liability in specific cases is the responsibility of courts, as well as other investigatory bodies. But as the secretary, Secretary [of State Antony] Blinken, has said, 'Those responsible for war crimes and other atrocities committed in Ukraine will be held to account.'"

-ABC News' Conor Finnegan