European markets posted their worst one-day drop in history on Thursday, as investors reacted to President Donald Trump 's decision to impose restrictions on travel to the U.S. from Europe, and the European Central Bank's decision not to cut interest rates.

The pan-European Stoxx 600 had plummeted 11% by the close, with travel and leisure stocks sinking 12.8% following Trump's announcement of a ban on European travel.

The U.K.'s FTSE 100 lost 9.8%, France's CAC 40 shed 12.3% and Germany's DAX fell 12.2%. Italian stocks finished nearly 17% lower, which was also the worst single-day loss for the FTSE MIB.

Trump said Wednesday that the U.S. will suspend all travel from 26 European countries to the U.S. for 30 days to curb the spread of coronavirus. The new rules will go into effect on Friday night. The measures will affect the nations in Europe that are part of the visa-free Schengen area. The U.K. and Ireland are exempted from the restrictions, as are American citizens who have undergone virus screening.

"These restrictions will be adjusted subject to conditions on the ground," Trump said, blaming Europe for not taking adequate action to control the spread of the virus; Italy is the worst hit country outside China and a nationwide lockdown continues there.

The World Health Organization (WHO) declared the coronavirus outbreak a pandemic on Wednesday. There are at least 120,000 confirmed cases of the virus worldwide and at least 4,717 people have died worldwide.

The European Central Bank decided Thursday not to cut interest rates, despite market expectations for a reduction amid the ongoing coronavirus outbreak, which disappointed markets and deepened the session's already significant losses. Analysts had expected a 10 basis point cut.

The central bank did announce measures to support bank lending, and expanded its quantitative easing (QE) program by 120 billion euros ($135.28 billion).