The United States restricted travel from China on February 2 and Europe from Europe on March 13. However, by March 8, covid-19 had spread in New York city communities. By March 15, the virus had been widely spread in the community. The virus that spreads most closely matches the strain that spreads in Europe rather than in China. President Donald Trump has repeatedly accused the virus of failing to stop its spread to the United States.
https://www. msn. com/en-us/travel/news/us-travel-bans-came-too-late-for-new-york-city-cdc-study-finds/ar-BB16PMvi