The Hague - The EU's medicines regulator has insisted it has the "most appropriate" method to approve a coronavirus vaccine, after Britain became the first Western country to give one the green light for general use.

The European Medicines Agency (EMA) says it will hold a special meeting by December 29 at the latest to decide on whether to grant conditional approval for the Pfizer-BioNTech vaccine.

However ministers in former EU member Britain claimed Brexit had allowed them to adopt the jab ahead of their European neighbours by freeing it from the 27-country bloc's rules.

Britain is still under EU drug marketing rules until December 31, the end of a post-Brexit transition period, but has approved the vaccine under an emergency provision in European law.

"EMA considers that the conditional marketing authorisation is the most appropriate regulatory mechanism for use in the current pandemic emergency," the agency said in an emailed statement to AFP Wednesday.

During public health emergencies, vaccine developers can ask the EMA for a conditional marketing authorisation to drastically speed up a process that normally takes years.

The EU watchdog said this involved a "controlled and robust framework" of studying data from lab studies and large clinical trials, before finally deciding whether to approve the vaccine.

"These are essential elements to ensure a high level of protection to citizens during the course of a mass vaccination campaign," it said.

The EMA was located in London until last year, but moved to Amsterdam as part of Britain's slow divorce from the European Union.

EU ministers earlier defended the EMA, with German Health Minister Jens Spahn saying: "The idea is not to be first, but to have a safe and efficient vaccine."