The European Commission has rejected bans introduced by Poland and Hungary on Ukrainian grain imports.
The two countries said the measures were necessary to protect their farming sectors from cheap imports.
The ban applies to grains, dairy products, sugar, fruit, vegetables and meats and will be in force until the end of June.
The Commission said it was not up to individual member states to make trade policy.
While the Commission has said that unilateral moves will not be tolerated, it has not yet specified what measures it would take against Poland and Hungary.
“In such challenging times, it is crucial to coordinate and align all decisions within the EU,” its spokesperson said in a statement.
Most Ukrainian grain is exported via the Black Sea, but Russia’s invasion last year disrupted export routes and resulted in large quantities of the grain ending up in central Europe.
A deal with Russia, brokered by the UN and Turkey, allows Ukraine to continue exporting by sea – but Ukraine accuses Russia of slowing the process with over-zealous inspections.
Poland and Hungary announced the move on Saturday. The decision came after complaints from local farmers who said they were being undercut by cheaper Ukrainian grain flooding their markets.
On Sunday, Polish Economic Development and Technology Minister Waldemar Buda clarified that the ban applied to goods in transit as well as those staying in Poland.