Gasum, Finland's natural gas company, announced Friday that it was informed its imports from Russia's Gazprom Export will be cut off on Saturday at 7 a.m. local time.

The move by Russia comes days after Finland submitted its application to join NATO.

“It is highly regrettable that natural gas supplies under our supply contract will now be halted. However, we have been carefully preparing for this situation and provided that there will be no disruptions in the gas transmission network, we will be able to supply all our customers with gas in the coming months,” Gasum CEO Mika Wiljanen said in a statement.

Gasum will supply natural gas to its customers from other sources though the Balticconnector pipeline, which connects Finland with Estonia, the company said in a statement.

Gasum said its gas-filling stations in the network area will continue in normal operation.

-ABC News' Alexandra Faul

Dozens of artillery systems supplied by the United States to Ukraine were not fitted with advanced computer systems, which improve the efficiency and accuracy of the weapons, ABC News has learned.

The M777 155mm howitzers are now being used by the Ukrainian military in its war with Russia.

The Pentagon did not deny that the artillery pieces were supplied without the computers but said it had received "positive feedback" from the Ukrainians about the "precise and highly effective" weapons.

That positive sentiment was echoed by a Ukrainian politician, who spoke to ABC News on condition of anonymity. However, the politician also expressed frustration that the artillery pieces had not been the fitted with the digital computer systems.

Artillery is currently playing a crucial role in the fighting across eastern Ukraine, as Russia continues its offensive in that part of the country. U.S. officials recently confirmed that all but one of the 90 howitzers promised to Ukraine had now been delivered, along with tactical vehicles used to tow them.

If fitted to a howitzer, the digital computer system enables the crew operating the weapon to quickly and accurately pinpoint a target. Howitzers without a computer system can still be fired accurately, using traditional methods to calculate the angle needed to hit a target.

Modern computer systems, however, rule out the possibility of human error. Why the artillery pieces supplied to Ukraine did not have the digital targeting technology installed is unclear. The Pentagon said it would not discuss individual components "for operational security reasons."

-ABC News' Tom Burridge and Luis Martinez

As many as 1,700 Ukrainian soldiers have likely surrendered from the Azovstal Iron and Steel Works plant in war-ravaged Mariupol this week, according to the U.K. Ministry of Defense.

"An unknown number of Ukrainian forces remain inside the factory," the ministry said Friday in an intelligence update. "Once Russia has secured Mariupol, it is likely they will move their forces to reinforce operations in the Donbas."

For weeks, Ukrainian fighters and civilians were holed up inside the sprawling industrial site as the remaining pocket of resistance to Russia's relentless bombardment of Mariupol, a southeastern Ukrainian port city strategically located on the Sea of Azov between eastern Ukraine's disputed Donbas region and the Moscow-annexed Crimean Peninsula. Russia claimed Thursday that 1,730 Ukrainian soldiers had surrendered in Mariupol over the previous three days, while Ukraine confirmed Tuesday that more than 250 had yielded in the initial hours after it ordered them to do so.

Mariupol is the largest city that Russian forces have seized since launching an invasion of neighboring Ukraine on Feb. 24. Its complete capture gives Russia total control of the coast of the Sea of Azov as well as a continuous stretch of territory along eastern and southern Ukraine.

"Staunch Ukrainian resistance in Mariupol since the start of the war means Russian forces in the area must be re-equipped and refurbished before they can be redeployed effectively," the U.K. defense ministry said. "This can be a lengthy process when done thoroughly."

"Russian commanders, however, are under pressure to demonstrably achieve operational objectives," the ministry added. "This means that Russia will probably redistribute their forces swiftly without adequate preparation, which risks further force attrition."

Nearly 28,000 Ukrainian citizens have arrived in Belarus since Russia invaded neighboring Ukraine on Feb. 24, according to the Belarusian State Border Committee.

"Between 6 a.m. on February 24 and 6 a.m. on May 20, a total of 27,868 Ukrainian citizens arrived in Belarus, including 15,793 who crossed the Ukrainian-Belarusian border, 10,563 by transit through Poland, 1,305 through Lithuania, and 207 through Latvia," the committee said in a statement Friday.

In the past 24 hours alone, 154 Ukrainian citizens arrived in Belarus, including 120 via Poland, according to the committee.

Belarus shares a land border with both Ukraine and Russia, and is Moscow's main ally.

White House national security advisor Jake Sullivan hinted Thursday of more sanctions coming against Russia in the "next week or two" aimed at targeting ways Moscow is evading sanctions already imposed.

“Where our focus will be over the course of the coming days is on evasion,” Sullivan said Thursday at the Economic Club of Washington. “As Russia tries to adjust to the fact that it’s under this massive economic pressure, what steps do they take to try to evade our sanctions and how do we crack down on that? And I think we'll have some announcements in the next week or two that identify targets that are trying to facilitate that evasion both inside Russia and beyond."

When Sullivan was asked whether sanctions will automatically be lifted if a negotiated peace deal between Russia and Ukraine is worked out, he appeared cautious with his words, saying, “a lot of that depends on what the shape and scope” of the agreement is.

“A lot of it depends on what the Ukrainians, in consultation with us and the Europeans come to agree to," Sullivan said. "You know, we're not going to do a deal over the head of the Ukrainians where we give a bunch of sanctions relief to Russia. But if some measure of sanctions relief were built in to some credible diplomatic solution led by the Ukrainians, that's something that we would happily discuss."

But Sullivan said Russian oligarchs shouldn't expect to ever get back their yachts and other assets seized under sanctions that have been imposed, saying the ultimate goal is "not to give them back” once the war is over.

“The president is actively looking at how we can deal with the fact that as we seize these assets, our goal is not to give them back. Our goal is to put them to a better use than that," Sullivan said. "But I'll be careful in what I say today because there's an ongoing kind of policy process around how we end up dealing with that question. But, rest assured, that the goal is not just to sit on them for a while."

-ABC News' Justin Gomez