European Union medicines regulator has approved new manufacturing sites for coronavirus vaccines made by Pfizer-BioNTech, Moderna and AstraZeneca, in a move that could significantly boost Europe’s supply of the shots.

In a statement published on Friday, the European Medicines Agency (EMA) said it had approved sites in the Netherlands, Germany and Switzerland for the COVID-19 vaccines made by the companies.

The new approvals come amid the 27-nation bloc’s struggles to ramp up COVID-19 vaccination and repeated delivery delays and manufacturing problems. The EMA said it had approved a factory in Leiden, the Netherlands, to make the active substance for AstraZeneca’s vaccine, bringing the number of such licensed sites to four.

"A new manufacturing site has been approved for the production of AstraZeneca's Covid-19 vaccine active substance," the Amsterdam-based EMA said in a statement, according to release carried by Agence France-Presse (AFP). "The Halix site is located in Leiden, the Netherlands, and will bring the total number of manufacturing sites licensed for the production of the active substance of the vaccine to four."

EU Health Commissioner Stella Kyriakides told AFP that the new vaccines would be delivered from the AstraZeneca plant within days following the EMA decision.

She said it had been made under an "accelerated" process.

"We now expect that vaccines produced by this plant will be delivered to EU member states in the coming days as part of the contractual obligation and commitment made by AstraZeneca to European citizens," she said in a statement sent to AFP.

Some EU countries had been "severely affected by the disappointing reduction in deliveries of AstraZeneca vaccines," Kyriakides said.

"Had it not been for the under deliveries from AstraZeneca, EU vaccination rates could have been almost twice as high," she said.

The Dutch plant has been at the center of a furious row, with British Prime Minister Boris Johnson's government claiming it as part of the British vaccine supply chain.

However, EU chief Ursula von der Leyen warned Thursday that it will ban firms including AstraZeneca from exporting vaccines to other countries until they meet their commitments to the bloc.

While the EU has talked tough, the Netherlands and Belgium, centers of EU vaccine production, are skittish at talk of an embargo, fearful that disruption to global supply chains could hurt other firms' production.

Dutch Prime Minister Mark Rutte said on Thursday that London and Brussels could agree on a deal on vaccine sharing by the weekend "or soon after" to avoid the imposition of an EU embargo.

But he added that he had warned Johnson that the Netherlands would enforce any EU decision to halt Halix exports.

"I explained to him that this is not how this works in Europe and that this is not a bilateral decision between us and the UK," Rutte said.

The EU regulator said it was also giving the green light to a site in Marburg, Germany, to make both the active substance and completed vaccine developed by BioNTech and Pfizer. And last week, an expert committee at the EMA recommended new manufacturing lines at a facility in Visp, Switzerland for the Moderna Inc. vaccine.

These changes are "intended to scale up production capacity and increase the supply of the vaccine for the EU market,” the regulator said, as reported by The Associated Press (AP). All COVID-19 vaccines meant for use in the EU must have their manufacturing sites approved by the EMA after a regulatory evaluation.