Kyiv on Tuesday accused the Red Cross of "inaction" over Ukrainian prisoners held by Russia, saying a lack of visits to detained soldiers and civilians meant they were vulnerable to being tortured.
"Unfortunately, at each exchange, we see that the International Committee of the Red Cross's inaction has led to our prisoners of war and civilian hostages being tortured daily by hunger, by electrocution," Ukrainian human rights commissioner Dmytro Lubinets said in a presidential statement.
He said the organisation was not fulfilling its mandate to visit military and civilian prisoners in conflict zones.
The prison in Kremlin-controlled Olenivka in eastern Ukraine, where dozens of Ukrainian prisoners of war died in a July bombing strike, has become a focal point.
The United Nations has warned of dire sanitary conditions for those remaining in the facility, with many PoWs reportedly suffering from infectious diseases.
Kyiv has repeatedly asked for an ICRC team to visit.
The presidency's chief of staff Andriy Yermak said: "Ukraine expects and demands from the ICRC the appropriate determination to gain access to Ukrainian prisoners in Olenivka".
"We do not see that the ICRC is working to protect our prisoners," Yermak said on Tuesday.
The ICRC told AFP that it shared Kyiv's frustration.
"We know that behind it there's the anguish of families at not knowing the fate of their loved ones," a spokesman said.
"We reiterate that we will never stop demanding access to all prisoners of war until we can see them several times where they are held," he added.
Last week, ICRC spokesman Ewan Watson said the Red Cross was eager to visit Olenivka, but had to wait until it was granted authorisation and security guarantees to make sure its teams were not in danger.
"We share the frustration regarding our lack of access to all prisoners of war held in the international armed conflict between Russia and Ukraine," Watson said.
"We have been able to visit hundreds of PoWs on both sides, but there are thousands more who we have not been able to see, and we are concerned about their fate," he told reporters on Friday.
The ICRC has called for "immediate and unimpeded access".
