The European Union wants pharmaceutical company AstraZeneca to deliver 120 million doses of its novel coronavirus vaccine by the end of June, a Belgian court has heard during a case about delayed vaccine orders.

The EU opened a second lawsuit against AstraZeneca on Tuesday, after first filing legal action against the company at the Brussels Court of First Instance back in April.

EU lawyers allege that AstraZeneca has not respected a contract for the supply of vaccines, and that the company has not made sufficient arrangements to ensure timely deliveries.

The cases focus on the apparent slow progress of a 300-million dose order. AstraZeneca initially agreed to complete the order by the end of June, though the company has only shipped 50 million doses so far.

On Tuesday, EU lawyers said the bloc would accept 120 million doses in June, followed by the completion of the total order in September. Lawyers also asked for symbolic compensation of 1 euro ($1.22) for what it calls a breach of contract by AstraZeneca, Reuters reported.

The EU has indicated it may push for more substantial financial penalties connected to the alleged delay.

Lawyers for AstraZeneca said the company hopes to deliver 100 million doses by the end of next month. They also complained about the EU opening a second legal case while the first is ongoing.

Meanwhile, European Commissioner for Internal Market Thierry Breton told French radio station France Inter on Sunday that the EU will not seek any new orders with AstraZeneca, and that, at present, the bloc intends to rely on Pfizer for the majority of future novel coronavirus vaccines.

"We have not renewed the order for after June. We'll see what happens," Breton said.

He added that AstraZeneca's vaccine was "very good" and did not rule out a potential renewal of the EU contract at a later stage, Reuters said.

Last week, the European Commission and Pfizer struck a major contract extension for a potential 1.8 billion doses through 2023.

Breton's comments confirm that the EU has performed a major pivot away from viral vector vaccines made by AstraZeneca and Johnson& Johnson toward messenger RNA vaccines from Pfizer and Moderna.

European Commission President Ursula von der Leyen first indicated this shift in strategy in April, when treatments from both AstraZeneca and Johnson & Johnson were subject to a series of investigations by health regulators about a possible link with rare forms of blood clotting.

The United Kingdom Department of Health moved to allay safety concerns about the AstraZeneca jab this week, following five recent suspected cases of vaccine-related blood clotting in Northern Ireland, out of a total 550,000 administered shots.

"The adverse reactions following the Oxford-AstraZeneca first dose are extremely rare," the department said in a statement on Monday. "The Medicines and Healthcare products Regulatory Agency emphasizes that, for the vast majority of people, the benefits of preventing serious illness and death far outweigh any risks."