BERLIN — As worries about vaccine delays swept across Europe, Pfizer and BioNTech said Wednesday they have finalized an agreement to supply the European Union with another 200 million doses of their COVID-19 vaccine.

The U.S. and German companies said in a statement that the doses come on top of the 300 million vaccine doses the bloc has initially ordered. The EU's executive Commission has an option to request a further 100 million doses.

They said the 200 million doses are expected to be delivered this year, with an estimated 75 million of them in the second quarter.

The Pfizer-BioNTech vaccine was the first of three so far to be approved for use in the EU, which has faced strong criticism for a slow start to its vaccination campaign compared with countries such as Israel, Britain and the United States. The other two EU-approved vaccines are from Moderna and AstraZeneca.

Delays to planned deliveries from all those vaccine manufacturers have helped fuel dissatisfaction among European governments.

Last month, Pfizer said it was temporarily reducing deliveries to Europe and Canada while it upgraded production capacity at its plant in Belgium. The EU also had a public spat with AstraZeneca over getting fewer of its vaccine shots than anticipated. AstraZeneca's chief blamed the lag on new factories needing to work out vaccine production issues.

"We are working relentlessly to support the further roll-out of vaccination campaigns in Europe and worldwide by expanding manufacturing capacity," Pfizer CEO Albert Bourla said Wednesday.

BioNTech CEO Ugur Sahin noted that his company will initiate production at its new plant in Marburg, Germany, this month and has strengthened its manufacturing network with further partners.

"We are continuing to evaluate, together with governments, authorities and partners at all levels, how we might address an even higher future supply requirement for our vaccines," he said.

Wednesday's statement didn't give financial details of the latest EU-Pfizer deal.

On Tuesday, the European Medicines Agency said it had received a request from Johnson & Johnson for its coronavirus vaccine to be authorized. The EU medicine regulator said it could issue an opinion by mid-March. The J&J vaccine is given in one shot, while the three other vaccines required two shots spaced weeks apart.