BERLIN (AP) — Europeans can look forward to traveling this summer, if coronavirus cases keep declining further on the continent, German Chancellor Angela Merkel said Saturday.

While the European Union is developing a vaccine certificate valid throughout the 27-nation bloc, summer vacations abroad should be possible again even for people who haven't had their shots against the coronavirus, she said.

“If you look at the low incidence (of COVID-19) that some of our European partner countries already have,...then I'm very hopeful that we can also generally afford to do what was possible last summer, too," Merkel said.

She cited the sharp drop in COVID-19 cases in Portugal in recent months after the country imposed a drastic lockdown.

Portugal had one of the highest infection rates worldwide in January, but by Friday the seven-day rolling average of daily new cases stood at 3.3 per 100,000 inhabitants - about a quarter of the rate in the United States.

Merkel said that Germany also appears to have broken its most recent outbreak.

“Step by step, more will be possible in Germany, too, wherever the incidence drops, and that will hopefully be the case for all of Europe,” she said.

Merkel spoke to reporters in Berlin, from where she took part remotely in a two-day EU summit that discussed, among other issues, the effort to develop a “green certificate” that would facilitate travel across the region this summer. Even if case numbers drop, some countries will likely impose restrictions - such as mandatory testing and quarantine - for travelers who can't prove they've been vaccinated or recovered from infection.

EU leaders discussed the technical requirements for such a certificate, which would record a person's vaccine status, and outstanding questions about how to treat people who received vaccines that weren't approved for use in the bloc.

The president of the European Commission, Ursula von der Leyen, said Saturday that the certificate was on track to be launched in June.

So far, about 30% of adults in the EU have received at least one dose of a coronavirus vaccine.