Brussels, Jul 2 (IANS): The European Union (EU) Digital Covid Certificate has officially came into force, allowing citizens and residents to have their pass issued and verified across the bloc.

By Wednesday evening, 21 out of the 27 EU member states, as well as Norway, Iceland and Liechtenstein, were connected to the system's network while the others were technically ready and joined the system on Thursday, reports Xinhua news agency.

Some countries already began using the new health certificate in June.

According to the European Commission, all member states should now be in a position to issue and accept the pass.

The EU Digital Covid Certificate is free and should be recognized by all 27 member states as well as Switzerland, Liechtenstein, Iceland and Norway.

The certificate will facilitate travel, helping to exempt holders from restrictions such as quarantine.

The EU had said it was in talks with several other countries, such as the UK and the US, over mutual recognition and operation of Covid-related documents.

The certificate applies in three situations: it attests whether a person has been vaccinated against Covid-19, whether they have had a recent negative test, or whether they are considered immune having previously contracted the disease.

Countries are obliged to accept vaccines approved by the European Medicines Agency (EMA), namely Pfizer/BioNTech, Moderna, AstraZeneca and Johnson & Johnson.

Welcoming its entry into application, European Commission President Ursula von der Leyen said that "the Certificate is a symbol of an open and safe Europe that is opening cautiously putting the protection of the health of our citizens first".

She said that more than 200 million certificates have already been generated.

Under the new rules, member states must refrain from imposing additional travel restrictions on holders of an EU Digital Covid Certificate, unless they are necessary and proportionate to safeguard public health.