There have been a number of reactions from the EU so far - some official, others not so much. I've decided, in the world of Twitter diplomacy, to count tweets from ministers and current/former heads of government as official responses for this purpose. Responses are in chronological order, culminating with the joint statement by President von der Leyen and President Michel.
The first response from a current or former head of government came from former Finnish Prime & Foreign minister, Alexander Stubb who tweeted at 5:18 UTC:
Any attempt to contain the #CoronaOutbreak is welcome, but the
decision of @realDonaldTrump to exclude the UK from a European
travel ban is nothing short of irresponsible. Viruses do not recognise
borders. Decisions should be based on facts, not politics.
The European Council President, Charles Michel, then tweeted his initial response at 6:12 UTC, saying that
Following the travel ban @realDonaldTrump announced, we will assess
the situation today.
Economic disruption must be avoided.
#Europe is taking all necessary measures to contain the spread of the #COVID19 virus, limit the number of affected people and support research.
Former Prime Minister of Romania & current leader of the Renew party in the European Parliament, Dacian Cioloş, tweeted that
Viruses know no borders or nationalities. Nationalism & blame games
are no antidote. This is a global crisis, which requires global
solidarity, @realDonaldTrump . Containment measures are needed, but
not arbitrary ones. Europe will be your partner, but not your
scapegoat. #COVID19
Speaking to BBC Breakfast, British Chancellor Rishi Sunak said that the UK had no plan to emulate the US travel ban. (I am aware the UK is no longer an EU member, but I feel this response is still relevant.)
We haven't believed that that's the right thing to do, the evidence
here doesn't support that.
What we are trying to do is contain the virus while recognising that
it is now likely that it will spread more significantly.
Guy Verhofstadt, former Prime Minister of Belgium, tweeted at 9:51 UTC that:
Nationalism isn't the answer to #COVID19, because viruses don't care
about borders or nationalities. We are all in this together. We need a
European approach to save lives & bold interventions to protect our
economy.
At 10:40 UTC, an official joint statement was released by President Ursula von der Leyen and President Charles Michel:
The Coronavirus is a global crisis, not limited to any continent and
it requires cooperation rather than unilateral action.
The European Union disapproves of the fact that the U.S. decision to
improve a travel ban was taken unilaterally and without consultation.
The European Union is taking strong action to limit the spread of the
virus.