A man walks in his apartment ruined after the Russian shelling in Kyiv, Ukraine, Monday, March 21, 2022. At least eight people were killed in the attack. (AP Photo / Efrem Lukatsky)

As Russia intensified its effort to pound Mariupol into submission, its ground offensive in other parts of Ukraine has become bogged down. Western officials and analysts say the conflict is turning into a grinding war of attrition, with Russia bombarding cities.

Ukrainian President Volodymyr Zelenskyy speaks to the U.S. Congress by video to plead for support as his country is besieged by Russian forces, at the Capitol in Washington, Wednesday, March 16, 2022. (AP Photo / J. Scott Applewhite, Pool)

Livestreamed into the Capitol complex, Ukrainian President Volodymyr Zelenskyy said the U.S. must sanction Russian lawmakers and block imports. But rather than an enforced no-fly zone that the White House has resisted, he instead sought other military aid to stop Russian assault.

People clear debris outside a medical center damaged after parts of a Russian missile, shot down by Ukrainian air defense, landed on a nearby apartment block, according to authorities, in Kyiv, Ukraine, Thursday, March 17, 2022. (AP Photo / Vadim Ghirda)

Hundreds of civilians had been taking shelter in the grand, columned theater in central Mariupol after their homes were destroyed in three weeks of fighting in the southern port city.

Volunteers pass an improvised path under a destroyed bridge as they evacuate an elderly resident in Irpin, some 25 km (16 miles) northwest of Kyiv, Friday, March 11, 2022. Kyiv northwest suburbs such as Irpin and Bucha have been enduring Russian shellfire and bombardments for over a week prompting residents to leave their home. (AP Photo / Efrem Lukatsky)

Russia widened its offensive in Ukraine on Friday, striking airfields in the west and a major industrial city in the east, while the huge armored column that had been stalled for over a week outside Kyiv was on the move again, spreading out into forests and towns near the capital.

In this image provided by the White House, President Joe Biden listens during a secure video call with French President Emmanuel Macron, German Chancellor Olaf Scholz and British Prime Minister Boris Johnson in the Situation Room at the White House Monday, March 7, 2022, in Washington. (Adam Schultz / The White House via AP)
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The action follows pleas by Ukrainian President Volodymyr Zelenskyy to U.S. and Western officials to cut off the imports, which had been a glaring omission in the massive sanctions put in place on Russia over the invasion.

People cross an improvised path under a destroyed bridge while fleeing the town of Irpin close to Kyiv, Ukraine, Monday, March 7, 2022. (AP Photo / Efrem Lukatsky)

A third round of talks between the two sides ended with a top Ukrainian official saying there had been minor, unspecified progress toward establishing safe corridors that would allow civilians to escape the fighting. Russia’s top negotiator said he expects those corridors to start functioning Tuesday.

  Ukrainians crowd under a destroyed bridge as they try to flee crossing the Irpin river in the outskirts of Kyiv, Ukraine, Saturday, March 5, 2022. (AP Photo / Emilio Morenatti)

Food, water, medicine and almost all other supplies were in desperately short supply in the port city of Mariupol, where Russian and Ukrainian forces had agreed to an 11-hour cease-fire that would allow civilians and the wounded to be evacuated. But Russian attacks quickly closed the humanitarian corridor, Ukrainian officials said.

Newlyweds Maria and David during their ceremony at a home, Saturday, March 5, 2022, in Oak Park, Ill. Maria, whom is from Ukraine, is headed back there to volunteer, a few days after she was married. (AP Photo / Matt Marton)

Maria and her fiancé, David, married Saturday before about 20 people in the backyard of an Oak Park home. On Monday, she plans to fly to Poland, then make her way to the Ukrainian border, ultimately aiming to volunteer to fight for her home country.

Militia men carry the coffin with the body of Volodymyr Nezhenets, 54, during his funeral in the city of Kyiv, Ukraine, Friday, March 4, 2022. A small group of reservists are burying their comrade, Nezhenets, who was one of three killed on Feb. 26 in an ambush Ukrainian authorities say was caused by Russian ‘saboteurs.’ (AP Photo / Emilio Morenatti)Militia men carry the coffin with the body of Volodymyr Nezhenets, 54, during his funeral in the city of Kyiv, Ukraine, Friday, March 4, 2022. A small group of r

Russian troops Friday seized the biggest nuclear power plant in Europe after a middle-of-the-night attack that set it on fire and briefly raised worldwide fears of a catastrophe in the most chilling turn in Moscow’s invasion of Ukraine yet.

Natalia, 57, cries as she says goodbye to her daughter and grandson on a train to Lviv at the Kyiv station, Ukraine, Thursday, March 3. 2022. (AP Photo/Emilio Morenatti)

Moscow’s advance on Ukraine’s capital in the north has apparently stalled, with a huge armored column outside Kyiv at a standstill. And stiffer than expected resistance from the outmanned, outgunned Ukrainians has staved off the swift victory that Russia may have expected.

Andrey Goncharuk, 68, a member of territorial defense wipes his face in the backyard of a house that was damaged by a Russian airstrike, according to locals, in Gorenka, outside the capital Kyiv, Ukraine, Wednesday, March 2, 2022. (AP Photo / Vadim Ghirda)

Russia reported its military casualties for the first time since the invasion began last week, saying nearly 500 of its troops had been killed and almost 1,600 wounded. Ukraine insisted Russia’s losses were far higher but did not immediately disclose its own casualties.

A member of the Ukrainian Emergency Service looks at the City Hall building in the central square following shelling in Kharkiv, Ukraine, Tuesday, March 1, 2022. Russian strikes pounded the central square in Ukraine’s second-largest city and other civilian sites Tuesday in what the country’s president condemned as blatant campaign of terror by Moscow. (AP Photo / Pavel Dorogoy)

Russian forces stepped up their attacks on crowded urban areas Tuesday, bombarding the central square in Ukraine’s second-biggest city and Kyiv’s main TV tower in what the country’s president called a blatant campaign of terror.

Cars are stopped at a roadblock set by civil defensemen at a road leading to central Kyiv, Ukraine, Monday, Feb. 28, 2022. (AP Photo / Emilio Morenatti)

An embattled Ukraine moved to solidify its bond with the West on Monday by signing an application to join the European Union, while the first round of Ukraine-Russia talks aimed at ending the fighting concluded with no immediate agreements.

An armored personnel carrier burns and damaged light utility vehicles stand abandoned after fighting in Kharkiv, Ukraine, Sunday, Feb. 27, 2022. (AP Photo / Marienko Andrew)

The directive to put Russia’s nuclear weapons in an increased state of readiness for launch raised fears that the crisis could boil over into nuclear warfare, whether by design or mistake.

Russian President Vladimir Putin speaks during a news conference in Moscow, Russia, Feb. 1, 2022. (Yuri Kochetkov / Pool Photo via AP, File)

The Holocaust, World War II and Nazism have been important tools for Putin in his bid to legitimize Russia’s moves in Ukraine, but historians see their use as disinformation and a cynical ploy to further the Russian leader’s aims.