Russia-Ukraine updates: 2 US veterans who joined Ukrainian forces missing

Gathering outside bombed churches, Ukrainians marked Orthodox Easter on Sunday in the capital of Kyiv and throughout the country with prayers for peace and the safety of soldiers fighting on the front lines.

Among those attending an Easter service at at Pyrohoshcha Dormition of the Mother of God Church in Kyiv was Inna Tsarkova, who told ABC News she was praying for the safety of her son, Roman, who she hasn't heard from in 11 days.

"(Easter) is much different because of the war. It’s supposed to be a very cheerful day. But right now we don’t know what the future is for Ukraine," Tsarkova said. "I hope he’s OK, that he will come back. There is no joy for Easter this year. Eleven days is a lot, it’s a lot for me to not talk with my son."

Elsewhere in Ukraine, worshipers gathered for an Easter service outside The Nativity of the Holy Virgin Church in the Kyiv suburb of Peremoha because the church was heavily damaged by Russian shelling. During the service, an Orthodox priest sprinkled holy water on believers lined up outside the church.

In Krakow, Poland, Ukrainian refugees lined the street outside the Orthodox Church of the Assumption for a Easter Mass.

About 200,000 displaced Ukrainians have sought refuge in Krakow, where the local Orthodox church has been struggling to provide shelter and humanitarian aid to the refugees.

Large TV screens were installed outside the Church of the Assumption so devotees who couldn't fit inside could participate in the service. Following the service, the church held a procession and blessing of food baskets that were given away to those in attendance.

Ukrainian Deputy Prime Minister Iryna Vereshchuk told ABC News that an anticipated visit to Ukraine on Sunday by U.S. Secretary of State Antony Blinken and Defense Secretary Lloyd Austin will focus on logistics of funneling more military assistance to the country's embattled troops to fight off Russian forces.

Vereshchuk told ABC News' foreign correspondent James Longman that the face-to-face visit will also give Ukrainian leaders a better chance to express the urgency and turmoil of their predicament.

"When you talk on the phone, the emotional part of the conversation cannot be conveyed," Vereshchuk said.

Vereshchuk said it is incumbent on NATO to step in, given Russia's apparent plans to take the Donbas region in eastern as well as territory in southern Ukraine.

She expressed disappointment in Germany for seemingly dragging its feet on sending heavy artillery, including tanks, to Ukraine and said it appeared German leaders are attempting to placate Putin.

“They don’t understand. There is no way to pacify Putin," Vereshchuk said. "It would be a huge problem for NATO if Russia has dominance over the Black Sea.”

German Chancellor Olaf Scholz has defended the support his country has sent Ukraine, saying last week, “The weapons we are delivering have made a very substantial contribution" to Ukraine fight against Russia."

"We are delivering, we have delivered and we will deliver," Scholz said.

Vereshchuk also told ABC News that about 200 Russian soldiers have been exchanged for Ukrainian soldiers, so far. She said the highest ranking Russian military leader captured by Ukraine was a lieutenant colonel.

Vereshchuk, who is in charge of prisoner exchanges for her country, said Ukraine won’t exchange those responsible for war crimes.

Vereshchuk also claimed that 200,000 Ukrainians have been forcibly deported to Russian-controlled territory into "filtration camps," including 5,000 children.

"We saw what Stalin did, we know what they are," Vereshchuk said of the camps.

Eight people were killed, including a 3-month-old infant, after Russian forces shelled the Black Sea port city of Odesa Saturday, Ukrainian officials said.

"The war started when this baby was 1 month old. Can you imagine what is happening?" Ukrainian President Volodymyr Zelenskyy said during a press briefing. "They are just scum. ... I don't have any other words for it, just scum."

Russian forces fired at least six cruise missiles, Anton Gerashchenko, an adviser to Ukraine's interior minister, said on Telegram. Ukrainian forces were able to shoot down two of the missiles, according to Zelenskyy, who said they were launched by Russian strategic aircraft from the Caspian Sea region.

"Residents of the city heard explosions in different areas," Gerashchenko said in on Facebook. "Residential buildings were hit."

"The only aim of Russian missile strikes on Odesa is terror. Russia must be designated a state sponsor of terrorism and treated accordingly. No business, no contacts, no cultural projects. We need a wall between civilization and barbarians striking peaceful cities with missiles," Ukrainian Foreign Minister Dmytro Kuleba said on Twitter.

Following the airstrike, the Russian Defense Ministry said that the Russian Aerospace Forces were targeting an airfield terminal outside Odesa storing "a large batch of foreign weapons" from the U.S. and European countries.

Ukrainian President Volodymyr Zelenskyy told reporters that U.S. Secretary of State Antony Blinken and Defense Secretary Lloyd Austin will visit Ukraine on Sunday.

Zelenskyy said they will discuss the list of weapons Ukraine needs and their delivery date.

A spokesperson for the State Department declined to comment and a spokesperson for the Defense Department said they had "nothing to offer" on the trip.

-ABC News' Jason Volack