The European Union looks set to keep the door shut to American travelers next month after officials discussed whom to allow back into the bloc as the coronavirus crisis subsides and governments ease border controls.

During a behind-closed-doors meeting on Wednesday, diplomats from the 27-nation EU in Brussels started to work out the criteria for lifting a curb on non-essential travel to the bloc as of July 1. They didn’t reach a conclusion and the conversation will continue on Friday, according to an official briefed on the outcome.

One of the criteria up for discussion is “reciprocity,” which would mean U.S. citizens wouldn’t immediately be allowed into the EU because Europeans are still barred for health reasons from traveling in the other direction. It’s likely that this factor will be combined with other metrics, including the rate of new Covid-19 cases, when deciding whom to bar, according to an internal document seen by Bloomberg News.

Europe is trying to revive domestic economies as the summer tourist season gets underway while guarding against a second wave of infections. The restrictions were introduced in mid-March for 30 days and extended three times through June as Europe battled to contain the coronavirus.

The EU faces a technical test in determining which foreigners should be allowed to travel to the bloc as of July 1 because the coronavirus outbreaks are in flux in numerous countries including the U.S. There are differences of opinion among the bloc’s governments over how to reopen external borders, with some countries insisting that reciprocity is more important than number of cases.

In Wednesday’s meeting, the European Commission told member states that it will also recommend using epidemiological criteria to assess which countries’ nationals should have access, the official said. The internal document circulated on behalf of EU governments before the meeting proposed a set of criteria for countries, including a comparable or better epidemiological situation than the average in the EU, giving as a current benchmark 16 new cases measured over 14 days per 100 000 people.

Currently, that would rule out people from countries including the U.S., Russia and South Africa. The final list is likely to comprise about 20 territories, an EU official said.

Anthony Fauci, the U.S. government’s top infectious-disease expert, told Congress Tuesday he was seeing a “disturbing surge” in new cases. California, Texas and Arizona reported their biggest daily jumps, and Florida’s infection rate climbed above 10%.

Closer to the EU, the western Balkans received a shock when tennis superstar Novak Djokovic of Serbia tested positive for the virus after an exhibition tour in the region.

A tennis star gets Covid-19, Balkans in shock.

The European Commission, the EU’s executive arm, recommended on June 11 that member-country governments draw up a common list of countries outside the bloc from which visitors would be allowed as of July 1 based on “objective criteria” and comparable epidemiological situations.

--With assistance from Ewa Krukowska, Ian Wishart and Nikos Chrysoloras.

This article was provided by Bloomberg News.