About 250 Ukrainian civilians have been evacuated from a chemical plant where they sought shelter in the besieged city of Severodonetsk in Eastern Ukraine, an official said.

Rodion Miroshnik, the Luhansk People's Republic ambassador to Russia, said the civilians were evacuated safely from the Azot chemical plant in Severodonetsk.

"Servicemen of the LPR People's Militia evacuated another about 250 people, including little children, from the premises of the Severodonetsk Azot plant," Miroshnik said on social media Sunday.

He added that the evacuation came a day after about 200 civilians were evacuated from the chemical plant.

Following months of heavy fighting, Russian troops took complete control of the Severodonetski over the weekend, according to Oleksandr Striuk, chief of the city's military administration.

One person was killed and six were injured, including a child, following a Russian missile strike Sunday in Ukraine's capital city, officials said.

The Russian shelling of Kyiv struck a residential building in the city, according to Kyiv Mayor Vitali Klitschko.

Klitschko said at least six people were injured in the attack, including a 7-year-old girl. He said the girl was undergoing surgery Sunday for non-life-threatening injuries.

Klitschko said the girl's mother was also injured in the attack.

A missile strike occurred in the Shevchenkivskyi neighborhood, near central Kyiv, officials said.

President Joe Biden on Sunday said Russia's early morning missile strikes on Kyiv were an act of "barbarism."

As Biden stood alongside German Chancellor Olaf Scholz at the official G7 welcome ceremony, ABC News' Karen Travers asked if he had any reaction to the strikes on a residential neighborhood.

"Yes, it's more of their barbarism," Biden said.

A missile struck an apartment block in Shevchenkivskyi, near central Kyiv, on Sunday morning, killing at least one and trapping others in the rubble, local officials said.

-ABC News' Sarah Kolinovsky

The Biden administration and other G7 leaders will announce on Sunday an import ban on Russian gold.

"This is a key export, a key source of revenue alternative for Russia, in terms of their ability to transact in the global financial system,” a senior administration official told reporters on a briefing call about the G7 summit in Germany. “Taking this step cuts off that capacity and again, is an ongoing illustration of the types of steps that the G7 can take collectively to continue to isolate Russia and cut it off from the global economy.”

The Treasury Department is expected to issue an official notice on Tuesday.

Gold is Russia's second largest export after oil and a source of significant revenue, but much of Russia's gold exportation has already been cut off in practice by banks, refiners and shippers. The move on Sunday marks an official severance of Russia from the world's gold market.

The U.S. and U.K. are participating in Sunday's announcement, but it is unclear whether all G7 countries will participate in the initiative. A Biden administration official tried to downplay concerns about potential disunity among G7 member states, pivoting instead to a talking point about efforts to cut off all financial pathways for Russia.

Pressed on whether Russia could continue to export gold by going through a country that does not participate in the ban, officials insisted the ban will be effective.

"We will continue to identify places where evasion as a risk continue to take steps to block off those pads,” an official said. “And the measuring gold in some ways is in fact, another step forward to block off ways that that Russia might seek to engage with the financial system, by virtue of all the other ways that have now been cut off to them.”

-ABC News’ Sarah Kolinovsky