Maximiliano Contreras raises the ticket number of his great-grandfather Alejandro Pavez, 91, for his turn to get a shot of a Chinese vaccine in Santiago, Chile, on Wednesday. (ESTEBAN FELIX / ASSOCIATED PRESS)

European leaders have shown an openness to the use of COVID-19 vaccines developed by any supplier, including Chinese ones, once they pass the European Union's tests.

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

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

A commission spokesman said that among 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.

We have always said that every vaccine trying to obtain approval from the European Medicines Agency is very welcome.

Angela Merkel, German Chancellor

German Chancellor Angela Merkel also said on 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 is very welcome," Merkel said.

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. For now, Hungary is the only EU member state that has authorized a vaccine from China and one from Russia.

Serbia has approved a wide portfolio that includes vaccines produced in Russia and China. The Balkans nation received a million doses of the Sinopharm vaccine in mid-January.

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Gains made in Asia

Chinese vaccines are also being welcomed in parts of Asia as mass vaccination campaigns gather pace.

Turkey is using an inactivated vaccine produced by Chinese pharmaceutical company Sinovac Biotech.

Turkey has so far received 13.5 million vaccine doses from China in three shipments as part of a procurement deal of 50 million. Over 2.2 million citizens have received their first shots since Jan 14, when the country's mass rollout began.

According to officials of the Turkish health ministry, the program is proceeding as planned, supported by high national confidence in Sinovac's vaccine.

Clinical trial results conducted in Turkey show the vaccine has an efficacy rate of 91.25 percent.

In Cambodia, Chinese vaccine specialists have provided training to medical staff on the procedures for care, storage, usage and transport.

"This emergency aid truly shows unbreakable ties and close cooperation between Cambodia and China and it will undoubtedly contribute further to building a community of a shared future between our two countries," Cambodian Defense Minister General Tea Banh said.

Tea Banh, who is also a deputy prime minister, is confident that the Chinese vaccine is safe and highly effective, and said the first batch of COVID-19 vaccines donated by China will be arriving in the country "soon".

Cambodian Prime Minister Hun Sen said the vaccines will be provided for free to people at a high risk of getting infected.

In Latin America, Chile on Wednesday launched its mass vaccination campaign against COVID-19, inoculating people over 90 years old at over 1,400 vaccination centers across the country.

The campaign is being carried out with almost 4 million doses of the Sinovac vaccine, which arrived aboard two flights last week, while are due to arrive over the coming weeks.

The Chilean government aims to vaccinate 5 million people in the first quarter of this year and 15 million by mid-2021.

In Colombia, President Ivan Duque announced on Wednesday that the country's National Food and Drug Surveillance Institute has authorized the emergency use of the Sinovac vaccine.

READ MORE: Chinese vaccines help countries battle COVID-19

Xinhua contributed to this story.