He went on: "After consulting with our top government health professionals, I have decided to take several strong but necessary actions to protect the health and wellbeing of all Americans.

"To keep new cases from entering our shores, we will be suspending all travel from Europe to the United States for the next 30 days. The new rules will go into effect Friday at midnight. These restrictions will be adjusted subject to conditions on the ground."

Full details of the ban are still emerging. Homeland Security said in a press release that most foreigners who have been to any Schengen Area country in the last 14 days would be barred from entering America.

The countries listed were Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, and Switzerland.

US citizens and their immediate family members, plus other legal US permanent residents, will be excluded from the ban.

During his address, which lasted around 10 minutes, Mr Trump read from a teleprompter as he attempted to reassure Americans that the virus would be defeated.

"No nation is more prepared or more resilient than the United States. We have the best economy, the most advanced healthcare, and the most talented doctors, scientists, and researchers anywhere in the world," Mr Trump said.

"We are all in this together. We must put politics aside, stop the partisanship and unify together as one nation and one family. As history has proven time and time again, Americans always rise to the challenge and overcome adversity.

"Each of us has a role to play in defeating this virus. Wash your hands, clean often-used surfaces, cover your face and mouth if you sneeze or cough, and most of all, if you are sick or not feeling well, stay home."