On 20 January 2020 the World Health Organization and the Chinese authorities confirmed the human to human transmission and outbreak of coronavirus, the director-general of the World Health Organization  Dr. Tedros Adhanom Ghebreyesus has said “The world is now in the grip of a coronavirus pandemic”, he expressed deep concern about “alarming levels of inaction” in the battle against the spread of Corona Virus which is now climbed into 118,000 cases in 114 countries.
He also said that in the past two weeks, the number of cases outside China has increased 13-fold, and the number of affected countries has tripled.“In the days and weeks ahead, we expect to see the many cases, the many deaths and the number of affected countries climb even higher.” Dr.Tedros
As 4,291 people reportedly died in the virus countries of the world are alarmed and start closing its borders. Kuwait banned all commercial flights, Netherlands announced tightened and entry restrictions to non-EU citizens, New Zealand announced that on March 19 it will close its borders to nonpermanent residents and noncitizens. Nigeria also expanded its restrictions especially to travelers from China, Italy, Iran, South Korea, Spain, Japan, France, Germany, the US, Norway, the UK, Switzerland, and the Netherlands.
Russia announces that they will close their borders on March 30 and ordered the civil authorities to shut down the flights, The US has banned the entry of all foreign nationals who have traveled to China, the Czech Republic,  Iran, Austria, EU, Norway, the UK or Ireland 14 days before their arrival.

Sources:

https://www.theguardian.com/world/2020/mar/11/who-declares-coronavirus-pandemic

https://www.aljazeera.com/news/2020/03/coronavirus-travel-restrictions-border-shutdowns-country-200318091505922.html