Russia claimed Wednesday that its military has taken complete control of Mariupol, a strategic port city in Ukraine's war-torn east.

"Peaceful life is being established in the territories of the LPR and DPR and Ukraine liberated from nationalists, including Mariupol, the largest industrial and transport hub on the Sea of ​​Azov," Russian Defense Minister Sergei Shoigu said during a teleconference. "It is under the control of the Russian army."

According to Shoigu, Russian forces have "securely blocked" remaining Ukrainian fighters on the grounds of the Azovstal Iron and Steel Works plant in Mariupol. The sprawling industrial site, which includes a maze of underground tunnels and bunkers, is the last pocket of Ukrainian resistance in Mariupol.

"In accordance with the instructions of the supreme commander, the remnants of the militants located in the industrial zone of the Azovstal plant are securely blocked around the entire perimeter of this territory," Shoigu told reporters. "Repeated proposals to the nationalists to release civilians and lay down their arms with a guarantee of saving lives and decent treatment in accordance with international law, they have ignored. We continue these attempts."

During a daily briefing call later Wednesday, Kremlin spokesman Dmitry Peskov said the situation at the blockaded plant hadn't changed and denied reports that Russian forces had begun storming the bombed-out territory, but said they have seen sporadic attempts by Ukrainian fighters to open fire.

"The supreme commander-in-chief has publicly ordered that the storm be canceled. There is no storm," Peksov told reporters. "We can see that escalations happen as the fighters come to firing positions. These attempts are suppressed quite rapidly."

ABC News recently spoke with Denys Prokopenko, a commander of the Azov Regiment, a far-right group now part of the Ukrainian military that was among the units defending Mariupol and is holed up inside the Azovstal plant with others. He said the fighters inside have tried to initiate a cease-fire to create conditions to allow people to flee but have yet to surrender, despite the odds. There are a number of people wounded and dead inside the plant, with some out of reach after sections of a bunker collapsed from Russian bombardment, according to Prokopenko.

"We are in full blockade, full circle of surrounding and we are under fire and the city is under fire," Prokopenko told ABC News.

Earlier this week, a humanitarian convoy evacuated more than 100 civilians from the Azovstal plant and escorted them safely to Zaporizhzhia, a Ukrainian government-controlled city located about 140 miles northwest of Mariupol. Hundreds more civilians remain trapped inside the plant and Russian forces have resumed shelling of the area, according to Ukrainian officials.

-ABC News' Clark Bentson, Dragana Jovanovic and Ian Pannell

The European Union's top official called on the 27-nation bloc on Wednesday to gradually ban oil imports from Russia as part of a sixth set of sanctions against Moscow for its war in Ukraine.

Addressing the European Parliament in Strasbourg, eastern France, European Commission President Ursula von der Leyen proposed that member nations "phase out" imports of Russian crude oil within six months and refined oil products from Russia by the end of the year. She also recommended sanctions targeting Russia's biggest bank and major broadcasters.

"We will make sure that we phase out Russian oil in an orderly fashion, in a way that allows us and our partners to secure alternative supply routes and minimizes the impact on global markets," von der Leyen said. "Thus, we maximise pressure on Russia, while at the same time minimising collateral damage to us and our partners around the globe. Because to help Ukraine, our own economy has to remain strong."

The proposals must be unanimously approved to take effect. Von der Leyen admitted that getting all 27 member countries to agree on oil sanctions "will not be easy." Hungary and Slovakia, both of which are highly dependent on Russian energy, have already demanded exemptions.

"Some member states are strongly dependent on Russian oil. But we simply have to work on it," she said. "We now propose a ban on Russian oil. This will be a complete import ban on all Russian oil, seaborne and pipeline, crude and refined."

President Joe Biden toured a Lockheed Martin facility in Troy, Alabama, where weapons systems such as Javelin anti-tank missiles are manufactured.

"The United States is leading our allies and partners around the world to make sure the courageous Ukrainians who are fighting for the future of their nation have the weapons and the capacity and the ammunition and the equipment to defend themselves against Putin's brutal war," Biden said at the facility.

To the Lockheed Martin employees, Biden said, "You make it possible."

"You're allowing the Ukrainians to defend themselves and quite frankly, they're making fools of the Russian military in many instances. A big part of the reason they've been able to keep up fighting and to make this war a strategic failure for Russia is because the United States together with our allies and partners have had their back," he said.

"You're changing people's lives," Biden said. "We built the weapons and equipment that helped defend freedom and sovereignty in Europe years ago. That’s true again today."

The president also urged Congress to pass his $33 billion supplemental aid package.

These highly lethal missiles can hit targets up to 2.5 miles away and have been key in Ukraine’s defense against Russia. The U.S. has sent over 5,500 Javelin anti-armor systems to so far, according to White House press secretary Jen Psaki.

-ABC News' Armando Tonatiuh Torres-García

Ukrainian troops are already putting U.S. howitzers into the fight against Russia, Defense Secretary Lloyd Austin told senators Tuesday.

During a Senate Appropriations Committee hearing on the 2023 defense budget, Sen. John Hoeven, R-N.D., asked Austin whether Ukrainian forces have the training they need to use the 90 American 155mm artillery systems the U.S. is sending to aid in the battle, especially in the eastern part of the country.

"They're using them as we speak," Austin said. "As you may know, we took a number of troops out and trained them up very quickly on 155s, put them back into action, and they are employing those weapons systems now."

A senior U.S. defense official told reporters Monday that some 200 Ukrainians have now been trained to use the M777 artillery pieces. The training was done by both U.S. and Canadian forces outside of Ukraine. Another 50 Ukrainians will begin howitzer training at an undisclosed location later this week.

The Ukrainian troops leaving the country to learn the American systems are already artillerymen, so training takes only about a week, according to U.S. officials. When they return they teach others what they learned.

Pentagon press secretary John Kirby told reporters on Monday that a "significant majority" of the 90 howitzers committed to Ukraine have arrived in country. The U.S. is also sending 184,000 artillery rounds for the weapons.

-ABC News' Matt Seyler

At least one person -- a journalist -- was killed in a rocket attack on a residential building in Kyiv on Thursday evening, ABC News has learned.

Kyiv Mayor Vitali Kilitschko said Friday that rescuers had found the body of a victim amid the rubble.

Radio Liberty, a service of the U.S.-funded Radio Free Europe/Radio Liberty, reported that one of its employees, Vira Gyrych, was killed when a Russian missile hit her apartment in the Ukrainian capital on Thursday. Her body was found beneath the wreckage Friday morning, according to the report.

Gyrych had worked as a journalist and producer for Radio Liberty's Kyiv bureau since 2018. Prior to that, she worked for leading Ukrainian television channels, according to Radio Liberty.

"The editorial staff of Radio Liberty expresses its condolences to the family of Vira Gyrych and will remember her as a bright and kind person, a true professional," Radio Liberty said in its report.

Israeli Ambassador to Ukraine Michael Brodsky also confirmed Gyrych's death in a Twitter post, saying she was a former employee of the Israeli embassy in Kyiv.

Thursday's rocket attack came as United Nations Secretary-General Antonio Guterres visited Kyiv. Five Russian missiles flew into the city, according to Ukrainian President Volodymyr Zelenskyy. At least 10 people were injured, including four who were hospitalized, according to the Kyiv City Council.