Poland said it had summoned Kyiv's ambassador on Wednesday over remarks by Ukraine's leader Volodymyr Zelensky at the UN that came amid a row over grain exports.
Zelensky said some nations feigned solidarity with Ukraine, prompting Warsaw to denounce comments "unjustified concerning Poland, which has supported Ukraine since the first days of the war".
Tensions between Warsaw and Kyiv, sparked by Poland's ban on Ukrainian grain imports to protect the interests of its farmers, have intensified in recent days.
The European Union's announcement on Friday that it was ending an import ban on Ukrainian grain in five member states inflamed tempers, triggering unilateral embargoes to which Kyiv responded by announcing that it would lodge a complaint with the World Trade Organisation (WTO).
Polish Prime Minister Mateusz Morawiecki warned on Wednesday that he would extend the list of Ukrainian products banned from import if Kyiv were to escalate the grain dispute.
A foreign ministry statement said that "putting pressure on Poland in multilateral forums or sending complaints to international courts are not appropriate methods to resolve differences between our countries."
Kyiv responded by calling on Poland to "leave emotion aside" after it had summoned its ambassador, urging Warsaw to adopt a "constructive" approach in the dispute.
