BRUSSELS, Feb. 4 (Xinhua) -- European leaders have shown an openness to the use of COVID-19 vaccines developed by any supplier once they pass the European Union's (EU) tests.

European Commission President Ursula von der Leyen said Tuesday that coronavirus vaccines from Russia and China could be approved for use in the EU if they "show all the data," AFP quoted the bloc's lawmakers as saying.

If Chinese producers "show all the data... then they could get... a conditional market authorization like the other ones," von der Leyen told EU lawmakers at a meeting.

A commission spokesman said Tuesday that one of the criteria for the EU contracts for vaccines was that producers had the capacity to produce them inside the bloc.

Europe is now facing a vaccine shortage as pharmacies are supplying vaccines slower than anticipated.

The EU has so far signed agreements with six vaccine suppliers but the vaccines approved by the bloc are from U.S.-Germany joint venture Pfizer and BioNTech, British-Swedish multinational AstraZeneca, and Moderna from the United States.

German Chancellor Angela Merkel said Tuesday that every COVID-19 vaccine is welcome in the EU as the bloc is facing vaccine delivery difficulties.

"Serbia is vaccinating faster. Serbia is vaccinating with the Chinese vaccine. We have always said that every vaccine trying to obtain approval from the European Medicines Agency (EMA) is very welcome," Merkel said in a televised interview with the German public broadcast ARD program "Farbe bekennen."

The German chancellor affirmed that by the end of summer everyone in Germany could be able to get at least the first of the two necessary vaccinations. So far nothing has gone wrong with the national vaccination campaign.

Merkel's remarks were echoed by French President Emmanuel Macron, who said that all vaccines that are approved by European and national health authorities will be welcome in France.

Decision-making on vaccine should be scientific, rather than political, Macron told TF1 television on Tuesday.

Spanish Health Minister Carolina Darias said Wednesday that Spain will be "open" to the use of the Russian Sputnik V coronavirus vaccine once authorized by the EMA.

For now, Hungary is the only EU member state that has authorized the use of China's Sinopharm COVID-19 vaccine and the Russian vaccine.

One of EU's Balkan partners, Serbia, has approved a wide portfolio that includes vaccines produced in Russia and China. The country received a million doses of China's Sinopharm vaccines in mid-January.