On Sunday, President of the European Commission Ursula von der Leyen told the New York Times that Americans and other travelers vaccinated with EU-approved vaccines will be able to freely travel in Europe starting this summer as part of the EU’s planned vaccine passport system.

“One thing is clear,” von der Leyen told the New York Times. “All 27 member states will accept, unconditionally, all those who are vaccinated with vaccines that are approved by the [European Medicines Agency].”

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So far, the EU has approved four COVID-19 vaccine jabs; those from British pharmaceutical firm AstraZeneca and American vaccine makers Pfizer, Johnson & Johnson, and Moderna. (The EU says that it has also secured doses or is in exploratory talks for four other vaccines, including ones from German firm CureVac and the U.S.’s Novavax.)

But at the moment, the European Medicines Agency (EMA) is not considering approving any Chinese-made jabs, suggesting that Europe’s vaccine passport system may leave out Chinese tourists and other travelers who have been vaccinated with the five China-made COVID-19 vaccines currently in use across the globe.

As of the end of March, China had distributed more than 115 million of its vaccines to over 70 countries, according to British research firm Airfinity. Domestically, China has also administered over 200 million doses of its own jabs as of last week.

People who’ve taken Russia’s Sputnik V vaccine or other inoculations the EMA has yet to approve will also be left out. But the omission of Chinese-made vaccines in particular could have major implications for Europe’s travel industry.

China is the world’s largest source of tourists and Europe’s second-most important travel partner behind the U.S. Before the pandemic in 2018, Chinese travelers made 6 million trips to Europe, and Europe was the second-most popular region behind Asia among Chinese tourists.

Tourism is a backbone of the EU’s economy; it’s responsible for 10% of the EU’s annual GDP and has helped create jobs for 26 million people, according to the United Nations World Tourism Organization. The EU is desperate for tourism to return this July and August, when roughly one-third of all hotel bookings for the year usually take place, after the pandemic ravaged last year’s summer season.

The EU Commission did not immediately return Fortune’s request for comment on von der Leyen’s remarks. It’s possible the decision to accept travelers inoculated with Chinese-made vaccines may be considered on a state-by-state basis by members of the bloc.

The South China Morning Post reported in March that individual EU countries may have the option to accept travelers inoculated with non–EU-approved vaccines. One EU member state, Hungary, has approved vaccine shots from Chinese makers CanSino and Sinopharm for domestic use.

But countries like France may be more resistant to accepting travelers inoculated with Chinese-made jabs. In February, French President Emmanuel Macron criticized Chinese vaccine makers for not releasing Phase III trial data to prove the efficacy of their vaccines and warned that it may be risky for other countries to approve and distribute the jabs.

Since then, only Chinese maker Sinovac has published efficacy results on its COVID-19 vaccine, albeit in a non–peer-reviewed journal.

China, meanwhile, has already launched its own digital vaccine passport system and appears to be opening the door to more travelers inoculated with non–Chinese-made jabs, pivoting away from an earlier stance that only recognized vaccine records from people who’d received Chinese-made jabs.

Last week, the Chinese embassy in the U.S. released a statement saying that it would acknowledge vaccination records from travelers inoculated with non–Chinese-made jabs from makers like Pfizer, Johnson & Johnson, and Moderna.

Currently, China has approved five vaccines for its domestic COVID-19 vaccine drive, and all five are made by Chinese pharmaceutical firms. China’s government is now reportedly considering the approval of its first foreign-made jab, the vaccine developed by Germany’s BioNTech and distributed locally by China’s Fosun Pharma. But the potential approval may not come until July.

Even if China loosens its vaccine passport criteria, it still limits incoming foreign travel to those making essential trips, such as people for coming to China on business or visiting relatives. And, vaccinated or not, all foreign or Chinese travelers are still required to undergo 14-day hotel quarantines once arriving in China.

China says that it is open to discussing mutual vaccine recognition with foreign countries for quarantine-free travel.

“China stands ready to advance mutual recognition of vaccination with other countries,” spokesman for China’s foreign ministry Zhao Lijian said in March.

But China has yet to finalize any such agreements yet, and it is unclear if it’s in discussions with the EU on mutually recognizing one another’s vaccines.

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