The State Department had on Wednesday launched improvements on sharing information with USA travelers to provide clear, timely and reliable safety and security information.
"Some areas have increased risk", the State Department advisory said.
Level 4 is for do-not-travel countries, those with a "greater likelihood of life-threatening risks" in which the US government may be limited in its ability to help.
While the state department is warning travellers to stay away from the five states categorised as level-four risk, Mexico as a whole is classified as a level two, where travellers should "exercise increased caution".
Level four means do not travel due to the greater likelihood of life-threatening risks. The states mentioned include "eastern Maharashtra and northern Telangana through western West Bengal" as well as " rural parts of Chhattisgarh and Jharkhand and... the borders of Telangana, Andhra Pradesh, Maharashtra, Madhya Pradesh, Uttar Pradesh, Bihar, West Bengal, and Odisha". Afghanistan was placed in Level 4, "Do not travel" category for reasons that included terrorism, civil unrest and armed conflict. But five Mexican states - Sinaloa, Guerrero, Michoacan, Colima and Tamaulipas - were given the highest rating of "do not travel", the same designation applied to near-failed states plagued by terrorism and open warfare.
Women have been discouraged from traveling alone as rape is "one of the fastest growing crimes in India". This program also remains a recommended path to receiving updates to travel advisories going forward.
US travelers were also warned to avoid unnecessary trips to the Central American nation of Guatemala due to the high criminal violence, sexual assault, armed robbery and gang-related offenses. It also advised its countrymen to not travel to Balochistan province, Khyber Pakhtunkhwa province, Federally Administered Tribal Areas among others.
The full travel advisory for Greece can be found here. Level three countries include Russian Federation, due to civil unrest in certain areas, and Venezuela, due to crime and a limited ability of the USA to provide assistance to citizens. "In the past, there have been large-scale terrorist attacks resulting in hundreds of casualties", it said.
"US citizens who travel overseas should always have a contingency plan for emergency situations".
The former due to crime and the US government's inability to provide aid to American travelers.
The State Department considers five states in Mexico as unsafe for US travelers as war-torn nations such as Syria, Yemen and Afghanistan.
Esponda said local officials and tourism operators are investing in increased security, including camera systems and the construction of a new marine base.