On March 18, the Central Epidemic Command Center (CECC) announced that the global coronavirus disease 2019 (COVID-19) outbreak has continued to expand. There have been more than 1,000 new cases per day in the United States, with four states experiencing community transmission, and more than 100 new cases per day in Canada and Australia, while New Zealand continues to maintain close ties with Australia. The US and Australia have also declared countrywide or regional states of emergency.

Given the risk of infection to Taiwanese nationals, effective March 19 the CECC will raise its travel notice for the US, Canada, Australia, and New Zealand, including for transit flights made through these countries, to Level 3: Warning. This comes in addition to the US states of Washington, New York, and California, which were already subject to a Level 3: Warning travel notice. Taiwanese nationals should avoid nonessential travel to these countries, and will be required to follow a 14-day period of home quarantine after returning from Level 3 countries and regions. Furthermore, effective March 19, all inbound travelers will be required to follow a 14-day period of home quarantine after entering Taiwan. 

As of March 18, the CECC has raised its travel notice for 97 countries and one region to Level 3: Warning; namely, mainland China (including Hong Kong and Macao), 20 Asian countries, nine Central Asian countries, 26 Schengen countries, the United Kingdom, the Republic of Ireland, 14 Eastern European countries, 16 countries and one territory in the Middle East, five north African countries, the US, Canada, New Zealand, and Australia. The Level 3 travel notice also applies to dependent territories of these countries where applicable.