BERLIN (AP) — 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 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 faces 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.

“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.

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 deal.