The Taoiseach has been in contact with EU Commission President Ursula von der Leyen to raise concerns about the decision to override part of the Northern Ireland Brexit protocol in order to block vaccines entering the UK.
The EU is introducing export controls on vaccines made inside the Union, following a row about shortfalls in the delivery of the Oxford AstraZeneca vaccine to member states.
Under the Northern Ireland Brexit protocol, all products should be exported from the EU to the North without checks or controls.
But the EU has invoked Article 16 of the protocol, which allows parts of the deal to be unilaterally overridden in certain circumstances.