Russia-Ukraine updates: US sanctions Russian military shipbuilder, diamond miner

The Ukrainian national flag was raised above the Chernobyl nuclear power plant Saturday at 11:00 a.m. local time, as workers sung the national anthem and celebrated the departure of Russian troops who had occupied the site for weeks.

"The flag-raising ceremony was attended by the station's operational personnel, who have been ensuring and continue to ensure the nuclear and radiation safety of the facilities during the difficult conditions of the occupation," Energoatom, Ukraine's state enterprise which operates its nuclear power stations, posted on its Telegram channel.

Roscosmos, the Russian state space corporation, said it will present the Russian government with proposals for discontinuing international cooperation on the International Space Station.

"Specific proposals from Roscosmos on the timeframe for ending cooperation on the ISS with the space agencies of the United States, Canada, the European Union and Japan will be submitted to our country's administration in the near future," Roscosmos CEO Dmitry Rogozin said on his Telegram channel.

Resumption of normal cooperation with ISS partners is only possible if the sanctions are fully lifted, Rogozin said.

"I believe that restoration of normal relations between the partners on the International Space Station and other joint projects is possible only if the illegal sanctions are lifted fully and unconditionally," he wrote.

Red Cross renewed its attempts to send a team to Mariupol on Saturday to evacuate civilians, after a team was unable to reach the city on Friday.

"Our team is on the move this morning from Zaporizhzhia to Mariupol. I'm not able to give further information at this stage," a Red Cross spokesperson said to Reuters.

An estimated 160,000 people are trapped in Mariupol.

A team on Friday had to abandon its plan to send 54 buses and many cars to Mariupol after it was unable to get security guarantees for the convoy.

Pope Francis told reporters Saturday that he is considering making a trip to the Ukrainian capital, Kyiv.

Asked by a reporter on the papal plane taking Francis from Rome to Malta if he was considering an invitation made by Ukrainian political and religious authorities, Francis answered: "Yes, it is on the table." He gave no further details.

The pope didn’t mention Russian President Vladimir Putin by name during his remarks, but said "some potentate" had unleashed the threat of nuclear war on the world in an "infantile and destructive aggression" under the guise of "anachronist claims of nationalistic interests."

"We had thought that invasions of other countries, savage street fighting and atomic threats were grim memories of a distant past," Francis added.

-ABC News' Rashid Haddou