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

About 631 residents of the bombed-out city of Mariupol in southeast Ukraine were able to evacuate on Thursday, according to a Ukrainian official.

Ukrainian Deputy Prime Minister Iryna Vereshchuk said the residents fled the city in private vehicles after 45 buses reserved to drive them out failed to make it into the city. Vereshchuk said another 600 civilians still in Mariupol plan to try to evacuate again on Friday.

Ukrainian President Volodymyr Zelenskyy said Thursday in an address to lawmakers of Australia, the Netherlands and Belgium that more than 90% of all buildings in Mariupol have been completely destroyed by Russian strikes.

"Thousands of peaceful Mariupol residents died, people are buried just in the city, in the courtyards of high-rise buildings, or rather, what is left of the high-rise buildings," Zelenskyy said.

-ABC News' Christine Theodorou

About 500 Ukrainian refugees were camped out Thursday outside the port of entry in Tijuana, Mexico, waiting to get into the United States after taking a circuitous route out of their war-torn country more than 10,000 miles away.

The number of Ukrainian refugees at the U.S. southern border entry point grew overnight from about 200 on Wednesday.

Immigration attorneys and humanitarian groups told ABC News that more and more Ukrainians have been showing up at the U.S. border this week, many of them getting there by flying to Mexico City, Mexico, and either taking a connecting flight to Tijuana or driving there.

Among the campers are also many Russians who oppose Russian President Vladimir Putin's decision to invade Ukraine, some telling ABC News they believe they would have been killed had they stayed in their homeland.

Ukrainians have asked for asylum in the United States and in many cases, have been allowed into the country under an exemption to Title 42, the federal policy that halted asylum claims during the pandemic. Some of the refugees allowed in the United States are being housed in San Diego, while others have spread out across the country.

Humanitarian groups are questioning the handling of the Ukrainians and Russians at the border versus all the other migrant groups fleeing horrific situations, including those coming from Haiti and Central America.

-ABC News' Will Carr

Russian troops are giving back control of the Chernobyl nuclear power plant to Ukraine, according to a letter from Russia's nuclear power company, Rosatom.

The site had been under the control of Russian forces since the invasion began on Feb. 24.

The letter is dated March 31 and was signed by Ukraine's nuclear regulator, Energoatom.

-ABC News' Fidel Pavlenko

Russian President Vladimir Putin has signed a decree requiring payment in rubles for gas exports.

As of Friday, Putin said all buyers from "unfriendly" countries -- including Germany, France and Poland -- must open ruble accounts in Russian banks, and contracts with parties who refuse will be deemed null and void.

President Joe Biden will be releasing one million barrels of oil per day from the strategic petroleum reserve for the next six months, according to the White House.

"Because of Putin’s war of choice, less oil is getting to market, and the reduction in supply is raising prices at the pump for Americans. President Biden is committed to doing everything in his power to help American families who are paying more out of pocket," the White House said in a statement Thursday.