EU Commission President Ursula von der Leyen said the contract is "crystal clear".
Ireland is set to receive around 300,000 fewer doses of the AstraZeneca vaccine due to a shortfall in EU supply.
1.4 million vaccinations in total were due to be delivered to Ireland in the first quarter of this year, but
RTÉ has reported that due to shortages of the AstraZeneca vaccine, Ireland will receive 1.1 million vaccinations instead.
The EU has been embroiled in a row with the Anglo-Swedish pharmaceutical company after it last week revealed it would cut deliveries in the first quarter due to production issues at a Belgian factory.
Speaking on Friday, European Commission head Ursula von der Leyen said the European Union's contract with AstraZeneca contains binding orders.
AstraZeneca’s chief executive, Pascal Soirot, has said the UK has first claim on doses of the vaccine produced in Oxford and Staffordshire in the UK.
Von der Leyen dismissed this claim and stated the contract is "crystal clear" and AstraZeneca is bound by the contract to deliver Covid-19 vaccine doses from it's UK production to the EU to make up for its shortfall in production in Belgium.
“There are binding orders and the contract is crystal clear,” von der Leyen told German radio station Deutschlandfunk.
“AstraZeneca has also explicitly assured us in this contract that no other obligations would prevent the contract from being fulfilled.”
In response to the "best efforts" clause, von der Leyen said this was no longer applicable as it referred to the period when the vaccine was in development.
She added: “This is now in the past. The vaccine is there. It still has to go through the approval process. Once a vaccine is there, there were very clear rules regarding amounts as well as timeframes – they are in the contract – and there are also locations where the vaccine should be produced.
“And it’s important, after the comments of the company boss, that we make this contract public so we can be transparent with citizens as to what was in this contract.”
