A humanitarian organisation in Poland has warned international donations of food, sanitary and medical supplies to Ukraine have more than halved since the start of the war.

The Help Ukraine Centre, based in the Polish city of Lublin, said the need for humanitarian aid is growing while the amount of aid donated is declining dramatically.

The centre's co-ordinator, Olga Rudnieva, told RTÉ’s Morning Ireland that humanitarian aid donations from European countries, including Ireland, have decreased in recent weeks.

"Humanitarian aid has gone down. People feel they have done enough but the situation is getting worse and aid is needed," Ms Rudnieva said.

"At the beginning of the war - the first week of our operations - we had approximately 15 to 18 trucks leaving our warehouse each day for Ukraine. Now it is six to seven trucks leaving our warehouse each day, which is not that many for a country as big as Ukraine," she said.

"In some of the occupied cities people haven't seen food for weeks and they've had a lack of water"

"I think a lot of people have a feeling that they have already helped Ukraine. But the need for humanitarian aid is growing and the amount of humanitarian aid coming to our warehouses and other warehouses is declining.

"More and more people are left without food, without their houses - the humanitarian crisis in Ukraine is deepening every day.

"In some of the occupied cities people haven't seen food for weeks and they’ve had a lack of water," Ms Rudnieva added.

The Help Ukraine Centre is a logistics hub which transfers aid from European countries and donors to Ukraine’s Ministry of Health, the Ukrainian Armed Forces, the Ministry of Reintegration and local humanitarian aid centres.

"This is a logistics hub transferring humanitarian aid from Europe to Ukraine. We get humanitarian aid from private individuals, from communities, from churches and from big companies. Then we send it to Ukraine where the Minister for Health receives it and distributes it," she said.

Ms Rudnieva is based in Poland as her husband remains in Ukraine.

"I am Ukrainian and for two months I haven’t been inside my house. Lots of my friends are in Ukraine starving. I have lost contact with many of them.

"My husband is on the street fighting for Ukraine. We do need help right now and we will need it in the coming months. The need will be growing," she added.