Forecasters suggested such a scenario would have caused huge economic damage and the likely emergence of a hard border with Northern Ireland.
The COVID-19 outbreak has brought the European economy to it knees and Italy, with the backing of France and Spain, wants a massive response from EU partners.
Trump's travel suspension will not affect travellers from the UK.
The talks take place just over a month since Britain ceased to be an EU member, and are meant to wrap up by the end of this year
Michel Barnier warned the bloc would not abandon its principles to get a deal and took aim at a British minister as tensions between the two sides ramped up.
The text, setting out the European Union's demands and red lines, is to be formally adopted Tuesday at a meeting of the bloc's ministers.
The drawn-out tussle for money is a Brussels ritual, but is especially problematic this time around because of Britain's departure from the EU.
German Chancellor Angela Merkel on the eve of the summit predicted "very tough and difficult negotiations" around the table.
It faces uncertainties caused by the grinding US-China trade war, Britain's departure from the European Union and now the deadly new coronavirus in China.
Britain has no official internet or social media regulator and is looking for ways to stop harmful online material from reaching children.
Relations between the two major economies have lingered for months in a tense truce.
He didn't rush -- as many other Brits in Germany did -- to secure citizenship following the 2016 referendum vote to quit the EU.
Prime Minister Boris set out a plan for his country to become a global champion of free trade.
The EU's poorer members, also agreed to fight any move to cut the EU Cohesion Fund reserved for the bloc's weaker economies.
The British premier will note London has been told in earlier divorce talks with Brussels that it has the option of an ambitious trade deal.
Nigel Farage described Brexit as "the greatest moment in the modern history of our great nation".
Daily business between the United Kingdom and the EU will continue as before during an 11-month transition until the end of the year.
Official celebrations will be muted out of respect for half the population who wanted to stay in the EU and who remain fearful of what lies ahead.
The UK will leave the EU at midnight Brussels time (2300 GMT) on Friday, but remain under most EU rules during a transition until the end of the year.
The first leg of a five-nation tour that also takes in Ukraine comes with Britain facing a historic crossroads as it parts ways with the EU on Friday night.
On eve of Brexit, there is a strong possibility that the Bank of England will later Thursday announce its first interest rate cut in more than three years.
Brexit to officially take effect on Friday at 2300 GMT, midnight for most of continental Europe and 11:00 pm in Britain.