TikTok, owned by the Chinese technology company ByteDance, announced on Sunday that it is immediately suspending live streaming and new content on its platform in Russia.

The video-focused social networking service said the move was in response to Russia's parliament passing a law governing what it called "fake news."

"TikTok is an outlet for creativity and entertainment that can provide a source of relief and human connection during a time of war when people are facing immense tragedy and isolation," TikTok said in a statement. "However, our highest priority is the safety of our employees and our users, and in light of Russia's new 'fake news' law, we have no choice but to suspend live streaming and new content to our video service in Russia while we review the safety implications of this law."

The company said its in-app messaging service will not be affected by the move.

"We will continue to evaluate the evolving circumstances in Russia to determine when we might fully resume our services with safety as our top priority," the company said.

On Friday, Russia's parliament amended Russia's criminal code to prohibit the spread of "fake" information and to punish violators with fines or jail terms of up to 15 years.

Russian leaders have previously accused the United States and its Western allies of sowing discord among the Russian people by using social media to disseminate false information about its conflict in Ukraine.

-ABC News' Christine Theodorou

American Express announced on Sunday that it is suspending operations in Russia and Belarus citing the "unjustified attack on the people of Ukraine."

The move came a day after Visa and Mastercard suspended operations in Russia.

"As a result, globally issued American Express cards will no longer work at merchants or ATMs in Russia. Additionally, cards issued locally in Russia by Russian banks will no longer work outside of the country on the American Express global network," American Express said in a statement.

The company said in its statement that it is also "terminating all business operations in Belarus," which has assisted Russia in its invasion of Ukraine.

American Express said the moves are in addition to previous steps it has taken, including halting its relationships with banks in Russia affected by the U.S. and international government sanctions.

During a Zoom call with U.S. lawmakers on Saturday, Ukrainian President Volodymyr Zelenskyy asked Visa and Mastercard to suspend their operations in Russia, according to a source on the call.

-ABC News' Matt Foster

Amid the war in Ukraine, two members of the country's volunteer military forces got married in an outdoor ceremony dressed in camouflage and wearing helmets.

Lesia Ivashchenko and Valerii Fylymonov, both members of the Ukrainian Defense Forces, exchanged marriage vows at a checkpoint in Kyiv surrounded by fellow soldiers, some wearing bullet-proof vests.

The bride carried a bouquet of roses and wore a helmet over her white wedding veil. The bride's helmet was removed when she and the groom sealed the nuptials with a kiss.

Kyiv Mayor Vitali Klitschko, the former World Boxing Organization's heavyweight champion, said he was able to greet the newlywed soldiers.

"They have been living in a civil marriage for a long time, and now they have decided to get married. The ceremony took place near one of the checkpoints set up at the entrances to Kyiv," Klitschko said on Twitter and included a video of the wedding.

Klitschko also noted that 457 babies have been born in the capital's maternity hospitals over the past 10 days.

"Life goes on!" Klitschko said. "And we will protect the life of Kyiv, Kyivites, our state!"

-ABC News' Julia Drozd

Management of Ukraine's Zaporizhzhya Nuclear Power Plant in southeastern Ukraine, Europe's largest nuclear power plant, is now operating under orders from the commander of the Russian forces that took control of the site last week, the International Atomic Energy Agency said Sunday.

IAEA Director-General Rafael Mariano Grossi warned that the Russian takeover of the plant violates an indispensable pillar of nuclear safety in which operating staff must be able to fulfill their safety and security duties and make decisions free of undue pressure.

The IAEA also said it has been informed by Ukraine's nuclear regulator that Russian forces have switched off some mobile networks and the internet so that reliable information from the site cannot be obtained through normal channels of communication. The regulator told the IAEA that staff operating at Zaporizhzhya are having major problems communicating outside of the plant because phone lines, email service and fax machines are no longer functioning.

Despite the communication issues, the regulator was able to provide updated information about the operational status of the Zaporizhzhya plant, confirming radiation levels there remain normal.

"I'm extremely concerned about these developments that were reported to me today. Just a few days after I presented the seven main elements of nuclear safety and security to the IAEA Board, several of them are already being compromised," Grossi said. "In order to be able to operate the plant safely and securely, management and staff must be allowed to carry out their vital duties in stable conditions without undue external interference or pressure."

Grossi added, "The deteriorating situation regarding vital communications between the regulator and the Zaporizhzhya NPP is also a source of deep concern, especially during an armed conflict that may jeopardize the country’s nuclear facilities at any time. Reliable communications between the regulator and the operator are a critical part of overall nuclear safety and security."

The nuclear regulator also reported that it is having problems communicating with personnel at the decommissioned Chornobyl Nuclear Power plant, the site of a 1986 nuclear disaster, saying only email communication is possible for now. The staff of more than 200 technical personnel and guards have not been able to rotate since Feb 23.

ABC News' Christine Theodorou

The Russian forces charging toward Kyiv haven't made progress in the last day as they face Ukrainian resistance and low food and gas supply, a senior U.S. defense official told reporters Tuesday.

However, it could be a deliberate pause, the official said. "Part of the stall could be ... as a result of their own self-determined sort of pause in operations -- that they are possibly regrouping, rethinking, reevaluating," the official said.

The U.S. believes Russian forces "have committed now more than 80% of what was their pre-staged combat power," the official added.

The official said some Russian soldiers weren't told they were going into combat. The official said "not all of them were apparently fully trained and prepared."

The strong Ukrainian resistance has also hurt morale, according to the official.

Russia has now launched more than 400 missiles on Ukraine, the official said. The U.S. believes Russia has launchers that could be used for thermobaric weapons, but cannot confirm their use, the official said.

Russian forces are making the most progress in the south. Russians are attacking Kherson in south Ukraine, which "appears very much to be contested city at this point," the official said.

Russians are also approaching Mariupol in southeastern Ukraine, and while they haven't yet entered the city, "they are close enough now that they could attack Mariupol with long range fires," the official said.

Two towns on the path to Mariupol are believed to be occupied by the Russians, according to the official.

The U.S. believes the Russians hope to move north out of Mariupol up to the heavily-contested city of Kharkiv. The official said they believe Russian forces are trying to encircle Kharkiv.

The U.S. official noted that they've seen "certain risk-averse behavior by the Russian military" over the last week.

"Take the amphibious assault, for instance. They put those troops ashore a good 70 kilometers away from Mariupol because they knew Mariupol was going to be defended and they could put them ashore in an uncontested environment. And they still haven't reached Mariupol," the official said.

"They are not necessarily willing to take high risks with their own aircraft and their own pilots," the official said.

"And of course we're seeing that on the ground -- the fairly slow and steady progress that they have made, and you guys are seeing it for yourselves on the ground where ... units are surrendering, sometimes without a fight."

-ABC News' Matt Seyler