When the U.S. Department of State detects a threat to Americans traveling abroad, officials issue warnings and alerts. The countries on this list change as per their latest crime and violence rates, and at times by natural disasters.

The latest to join these ranks is North Korea. While the country has always been remote and rather troublesome, their recent nuclear advances and violent rhetoric against the West has raised concerns.

There are no direct travel connections between the U.S. and North Korea, but Americans have still been able to visit North Korea as tourists. With the rise in tension between the nations, however, the State Department on Aug. 10 issued a travel warning to restrict the use of U.S. passports to travel into or through North Korea, effective Sept. 1.

The tragic death of American student Otto Warmbier in Pyongyang, North Korea, and the repeated nuclear tests carried out by that country has led to new economic sanctions and travel bans. Some have pointed out that these bans mark a return to Cold War-era restrictions since the usual State Department alerts are just warnings and not complete travel bans.

But the increasing intensity of North Korea's nuclear weapons program has officials worried. The risk of arrest and long-term detention of U.S. citizens in that country means grave danger for travelers.

While the U.S. bans have taken a hard stance against North Korea, Canada has decided to leave travel options open, despite their concerns. Instead of an outright ban, they have strongly advised Canadian passport holders from going to or through the secret state of North Korea. Since there is no resident Canadian government office in the country, travelers in trouble will find it nigh impossible to get consular assistance in North Korea.

The latest North Korean intercontinental ballistic missile (ICBM) tests and reports of "unprecedented levels" of submarine activity have caused an uncertain security situation in the region. Canadian Prime Minister Justin Trudeau condemned these actions as irresponsible and provocative, while U.S. President Donald Trump has promised "fire and fury" and said the military is "locked and loaded" should North Korean leader Kim Jong Un attempt anything.

Among the other nations, another recent travel warning for U.S. tourists is for Somalia. Increasing criminal activity and widespread acts of terrorism are leading to civilian, tourist and government attacks. A region that has witnessed violence and unrest for decades now is facing a new crisis.

Along with the already escalated terrorism, Somalia is now a haven for self-proclaimed Islamic State of Iraq and ash-Sham (ISIS) and the Al-Qaeda-affiliated terrorist group, Al-Shabaab. Illegal roadblocks and other violent incidents are common, and kidnappings, bombings and murders are rampant as well, especially for U.S passport holders. Pirate attacks are common as well, so sailing and cruising these shores is not advised.

With no U.S. embassy presence in Somalia, help for American tourists may be hard to come by.

Venezuela is another country on the travel warning list, following an increase in violent crime and social unrest. The U.S. Department of State has issued strong warnings for U.S. citizens traveling to that country. Along with the security concerns, the country is also facing pervasive food and medicine shortages.

With the political situation volatile and unpredictable at the moment, arrests and detention of individuals, including U.S. citizens is highly possible. In such cases, individuals may very well be denied access to proper medical care, even clean water and food.

U.S. tourists also need to be alert much closer to home as the State Department has also recently issued a travel warning for Mexico, following the death of an American tourist and ensuing stories of the same nature from other travelers. U.S. citizens traveling to Mexico need to be cautious, especially when they are drinking since there is now substantial evidence of tainted alcohol being served to tourists.

Travelers have been asked to drink in moderation and from trusted sources. If they experience symptoms of alcohol poisoning or feel even a little unwell, they should seek medical attention right away.

Ever since the death of the American tourist was reported, more people have come forward about their harrowing experiences. Both men and women have reported blackout incidents followed by robbery, sexual assaults and broken bones.

These warnings make it clear that when it comes to traveling in foreign countries, it's always best to stay alert.