Northern Ireland's Deputy First Minister has called for "cool heads" and solidarity in the fight against Covid-19.
The Sinn Féin vice-president's comment come after a dispute between the European Union and vaccine maker AstraZeneca, after the company said they would not be able to supple the bloc with the agreed upon number of vaccine doses due to manufacturing issues at their Belgian plant.
The EU moved to trigger Article 16 of the Northern Ireland Protocol, part of the UK's Withdrawal Agreement from the EU, to avoid Northern Ireland being used as a backdoor for vaccine doses to be imported to the UK from EU countries.
The EU faced criticism for the decision and ultimately made a U-turn, with Ms O'Neill saying she was concerned with the lack of consultation prior to the original decision being made, adding it was "unwise".
This unilateral action was clearly unwise, ill-judged and totally unnecessary.
"I have spoken to the Irish Government and expressed my serious concerns that the EU did not consult with the political administrations on this island, before moving to trigger Article 16.
“This unilateral action was clearly unwise, ill-judged and totally unnecessary. I welcome the fact the decision has now been reversed.
“Regrettably it has caused political harm," Ms O'Neill said.
Earlier, Northern Ireland's First Minister Arlene Foster described the EU's move as "absolutely disgraceful", with Taoiseach Micheál Martin also said to have expressed his concerns to the European Commission president, Ursula Von Der Leyen.
The Irish protocol, while imperfect, must be preserved.
Ms O'Neill added: "[The decision] has given those shameless Brexiteers now opposes to the consequences of their own actions, the opportunity of using it to their advantage.
"However the Irish protocol, while imperfect, must be preserved. The protocol exists as a solution to avoid a hard border on the island, thereby enabling the all-island economy and Good Friday Agreement to be protected."
She added the onus was on the EU and British government to "honour and implement" the Withdrawal Agreement and Northern Ireland Protocol.
"Our citizens need timely access to lifesaving vaccines, not trade disputes between the EU and the British government."
