Russia denied involvement in a rocket attack that killed dozens of people at a train station in eastern Ukraine on Friday.

Kremlin spokesman Dmitry Peskov alleged that the involvement of Russian forces in the attack on the railway station in the Ukrainian city of Kramatorsk was already ruled out by the Russian Ministry of Defense, based on the type of missile that was used -- a Tochka-U short-range ballistic missile.

"Our Armed Forces do not use missiles of this type," Peskov told reporters during a press briefing Friday. "No combat tasks were set or planned for today in Kramatorsk."

The head of the European Commission, Ursula von der Leyen, and the bloc's top diplomat, Joseph Borrell, were due to arrive in Ukraine's capital on Friday.

While in Kyiv, the pair will meet with Ukrainian President Volodymyr Zelenskyy. It will be their first visit to the Ukrainian capital since Russia launched its invasion on Feb. 24.

At least 30 people were killed and more than 100 others injured in a rocket attack on a railway station in eastern Ukraine on Friday morning, authorities said.

According to Ukraine's state-owned railway company, two Russian rockets struck the train station in the city of Kramatorsk in Donetsk Oblast.

"This is a purposeful strike on the passenger infrastructure of the railway and the residents of the city of Kramatorsk," Ukrainian Railways said in a post on Facebook.

Donetsk Oblast Gov. Pavlo Kyrylenko said the station was teeming with civilians fleeing the Russian invasion. Kyrylenko accused Russian forces of wanting "to take as many peaceful people as possible."

"Thousands of people were at the station during the missile strike, as residents of Donetsk Oblast are being evacuated to safer regions of Ukraine," Kyrylenko said in a post on Telegram.

Ukrainian President Volodymyr Zelenskyy confirmed that "thousands of peaceful Ukrainians were waiting for evacuation" when the rockets hit the station.

"Not having the strength and courage to confront us on the battlefield, they are cynically destroying the civilian population," Zelenskyy said in a post on Facebook. "This is an evil that has no limits. And if it is not punished, it will never stop."

Graphic images provided by Ukrainian officials showed the aftermath of the attack -- bodies lying on the ground next to scattered luggage and debris, with charred vehicles parked nearby.

Russian forces in northern Ukraine have now fully withdrawn to neighboring Belarus and Russia, the U.K. Ministry of Defense said Friday in an intelligence update.

"At least some of these forces will be transferred to East Ukraine to fight in the Donbas," the ministry added. "Many of these forces will require significant replenishment before being ready to deploy further east with any mass redeployment from the north likely to take at least a week minimum."

Meanwhile, cities in eastern and southern Ukraine continue to be shelled by Russian forces as the troops advance "further south from the strategically important city of Izium which remains under their control," according to the ministry.

President Joe Biden on Thursday announced a new $800 million security assistance package to help Ukrainians fighting in the eastern Donbas region. This funding includes heavy artillery weapons, tactical drones and howitzers.

This package includes 72 new howitzers. Combined with the 18 howitzers announced last week, the 90 howitzers headed to Ukraine can equip five battalions, according to the administration.

Biden noted that he’s run out of pre-approved money and equipment to send to Ukraine and he appealed to Congress to approve more.

When pressed by ABC News on how long the U.S. can sustain this level of spending, Biden said, “We have the capacity to do this for a long time."

He went on, "The question is, are we going to continue to maintain the support of the international community? And keep the pressure on Putin to prevent him from overrunning the country, No. 1, and No. 2, make sure we continue to maintain the economic sanctions, which, over time, and we're beginning to see, they’re devastating their economy and their ability to move forward."

Biden also announced a separate $500 million in economic aid to Ukraine to help fund government operations like salaries, pensions and social programs.

The president added that the U.S. is now banning Russian-affiliated ships from American ports.

Biden met with Ukrainian Prime Minister Denys Shmyhal Thursday morning ahead of his remarks.

-ABC News' Luis Martinez and Sarah Kolinovsky