BRUSSELS (Reuters) – AstraZeneca boss Pascal Soriot said on Thursday he hoped to meet the European Union’s expectations on the number of COVID-19 vaccines the company can deliver to the bloc in the second quarter, after big cuts in the first three months of the year.

The Anglo-Swedish drugmaker has been under fire in the EU for its delayed supplies of shots to the 27-nation bloc, which ordered 300 million doses by the end of June.

“We are working 24/7 to improve delivery and hopefully catch up to the expectations for Q2,” Soriot told EU lawmakers in a public hearing.

Under its contract with the EU, the company has committed to delivering 180 million doses in the second quarter.

Soriot did not mention the 180 million target, but said he was confident the company will be able to increase production in the second quarter using factories outside the EU that had no production problems, including in the United States.

He confirmed the company was trying to get 40 million doses of the COVID-19 vaccine to the EU by the end of March, which is less than half the amount it promised for the quarter in its contract.

The EU, which has fallen far behind the United States and former member Britain in vaccinating its public, has repeatedly urged the firm to deliver more.

Lower-than-expected yields – the amount of vaccine that can be produced from base ingredients – at its factories hurt output in the first three months.

Asked about supplies to Britain, which relies on the same factories used by the EU, Soriot said the former EU member with a population of around 66 million was smaller, and noted that most doses produced in the EU were used to serve the EU which has a population of about 450 million.

Executives from rival drugmakers that have developed or are testing COVID-19 vaccines, including Moderna Inc and CureVac NV were also part of the panel.

But most questions were directed at Soriot amid anger that the company has failed to deliver promised vaccine quantities to the bloc on schedule.

Moderna Chief Executive Officer Stephane Bancel said the company has experienced fluctuations as the U.S. biotech group ramps up output of its COVID-19 vaccine.

He said usually a company would stockpile product ahead of a launch, but it is shipping every dose it makes, leaving it without any spare inventory.

His comments came a day after the company increased its output target for this year and 2022 as it invests in additional manufacturing capacity.

(Reporting by Josephine Mason in London and Francesco Guarascio in Brussels; Editing by Susan Fenton, Bill Berkrot and Keith Weir)