Brussels, Feb 1 (IANS): Pharmaceutical company AstraZeneca has promised to increase its vaccine supply to the European Union (EU), European Commission President Ursula von der Leyen said.

The Anglo-Swedish pharmaceutical company will deliver 9 million additional doses in the first quarter of this year, bringing the total quarterly supply to 40 million, compared to last week's offer, von der Leyen said on Twitter on Sunday, Xinhua news agency reported.

The company "will start deliveries one week earlier than scheduled," she added, and it will also expand its manufacturing capacity in Europe.

The message came as a relief after a heated quarrel between the bloc and the company over the latter's limited capacity to deliver on its commitment, after the company announced last week to considerably reduce the amount of doses to the EU.

Media reports revealed that the drug giant had agreed to provide 80 million doses for the first quarter, but withdrew from the promise after an alleged disruption in its EU supply chain.

The AstraZeneca was the first vaccine producer that the EU has signed an early purchase agreement with in the effort to prevent the Covid-19 from further spread.

According to the agreement signed last August, the European Commission, on behalf of the EU states, purchased 300 million doses, with an option to buy 100 million more.

The AstraZeneca vaccine was approved for conditional marketing in the EU on Friday, after the European Medicines Agency gave a positive assessment for its safety and effectiveness. It was the the third Covid-19 vaccine greenlighted by the EU.

As the world is struggling to contain the pandemic, vaccination is being rolled out across the whole EU with the already-authorized coronavirus vaccines.

Meanwhile, 236 candidate vaccines are still being developed worldwide -- 63 of them in clinical trials -- in countries including Germany, China, Russia, Britain and the United States, according to information released by the World Health Organization on January 26.