The woman said that her husband asked her how she was, but that the line broke off before he could say anything about himself.
She said the phone call was possible under an agreement between the governments of Ukraine and Russia and thanks to the mediation of the Red Cross, which has been visiting some of the Ukrainian fighters.
Prokopenko, who spoke to The Associated Press in Kyiv together with another wife of a soldier, Yuliia Fedosiuk, said that the Ukraine and Russia agreement guarantees proper burial of dead soldiers and certain conditions for the prisoners of war, including allowing them to hold telephone calls with family members a few times per week.
The two women said several families had received calls in the past two days.
They said they could not reveal more details of the agreement but they were hopeful that the soldiers would not be tortured and that they eventually will "come back home."
The UK Ministry of Defense tweeted on May 20 that up to 1,700 Ukrainian soldiers might have surrendered at the Azovstal steelworks in Mariupol, which had been encircled and besieged by Russian troops for months.
On May 19, the International Committee of the Red Cross reported that they had recorded the personal data of "hundreds" of fighters who were evacuated from Azovstal.
Read also: Video of Azovstal evacuation emerges
The General Staff of the Armed Forces of Ukraine said that the commanders of the units stationed at Azovstal had received an order from the top military leadership to save the lives of their wounded soldiers.
Prior to that, the Azov Regiment issued a statement saying that the defenders of Mariupol had complied with the order and hoped for the support of the Ukrainian people.
According to Ukrainian Deputy Defense Minister Hanna Malyar, there was no other way to save the soldiers in Azovstal. She said that the operation to rescue the defenders of Mariupol would continue until they return to the territory controlled by Ukraine.
Ukrainian President Volodymyr Zelensky confirmed that the defenders of Mariupol should be released as part of a prisoner swap.