U.S. pharmaceutical company Moderna says it will supply the European Union with 80 million doses of its experimental COVID-19 treatment following preliminary discussions.

Under the potential deal the EU and its members have the option to buy 80 million additional shots of the vaccine.

Moderna appreciates the European Commission's partnership in helping Europeans get access to a safe and effective treatment, its chief executive officer Stephane Bancel said. "We're proud that the EC values the potential of our mRNA vaccine technology," Bancel said.

The U.S., UK and the EU are at the forefront of securing candidate COVID vaccines. As the number of COVID-19 deaths exceed 800,000 internationally more countries around the world are working to secure vaccine supplies.

A third-stage test of Moderna's experimental drug, which started July 27, continues and the Cambridge, Massachusetts-based biotechnology company hopes to have enrolled around 30,000 subjects by September. Moderna wants to develop and produce around half a billion shots a year starting in 2021. However, it could double that.

Moderna said Friday around 44 percent of its target number of 30,000 participants had already been registered in the final-stage research called COVE. The EU has announced plans for hundreds of millions of shots of drugs being developed by biotechnology companies AstraZeneca PLC, Johnson & Johnson, Sanofi S.A. and GlaxoSmithKline PLC and CureVac.

Moderna has already sealed an agreement with the U.S. for around 100 million COVID-19 vaccine doses for roughly $1.5 billion. A vaccine is badly needed to stop COVID-19 from spreading further.

Currently, more than 180 programs are being funded to develop a treatment. On Monday Italy said it had started its advanced-phase testing of an experimental drug developed by biotechnology group Reithera.