KYIV, Ukraine– Kyiv on Monday said it had filed lawsuits at the World Trade Organisation (WTO) against its three EU neighbours -- Poland, Slovakia and Hungary -- over their bans on Ukrainian grain imports.

The Central European countries went against a decision by the European Commission last week to end the import ban, with Kyiv warning of legal action.

The import bans have led to an awkward diplomatic spat with Poland, Kyiv's staunchest ally against Russia.

"It is crucially important for us to prove that individual member states cannot ban imports of Ukrainian goods," Ukraine's economy minister Yulia Svyrydenko said in a statement.

"That is why we are filing lawsuits against them."

"At the same time, we hope that these countries will lift their restrictions and we will not have to settle the matter in courts for a long time," Svyrydenko added.

She said Ukrainian exporters "continue to suffer significant losses" over the bans.

The import ban is particularly sensitive in Poland, where elections take place next month.

The current populist right-wing government of the Law and Justice party has strong support in farming regions.

Poland later said the legal proceedings would not change its position and that it would maintain the ban.

"We maintain our position, we think it is correct, it results from an economic analysis and powers derived from EU and international law," said government spokesman Piotr Mueller on Polsat News.

"A complaint before the WTO doesn't impress us."

Russia's invasion has hugely disrupted Ukrainian grain exports in the Black Sea, resulting in the EU becoming a major transit route and export destination for Ukrainian grain.

Poland, Slovakia and Hungary defied a European Commission decision to end restrictions on Ukrainian grain, extending their bans.