In the wake of Sunday night's Las Vegas shooting and multiple hurricanes across the United States and its territories, several countries are warning its citizens to avoid traveling to the U.S. unless it's absolutely necessary. The United Kingdom's foreign travel advice page says that terrorists are "very likely to try to carry out attacks in the USA" and urges people to avoid Las Vegas.
Ireland echoes those sentiments. Meanwhile, Germany lists "frequent political demonstrations" and "politically motivated violence" as reasons to be vigilant while traveling in America. It also points out that "in the U.S. it is comparatively easy to get possessions of weapons." Canada cautions its people to "avoid non-essential travel to the Florida Keys and Naples due to damage caused by Hurricane Irma." Australia cites both Hurricanes Maria and Irma, as well as the fact that "mass shootings continue to occur in public places."
Source: NY Daily News