The United States Department of State has warned its citizens against travelling to 23 countries classified under its highest travel advisory level, Level 4: Do Not Travel.

The department’s Bureau of Consular Affairs issued the warning in a post on its official Facebook page on Monday, explaining that the classification was based on local conditions and the US government’s limited ability to assist its citizens in the affected countries.

It said, “Level 4 means DO NOT TRAVEL. We assign Level 4 based on local conditions and/or our limited ability to help Americans there. These places are dangerous. Do not go for ANY reason.”

The 23 countries listed under the advisory are Afghanistan, Belarus, Burkina Faso, Burma, the Central African Republic, Chad, the Democratic Republic of the Congo, Haiti, Iran, Iraq, Lebanon, Libya, Mali, Niger, North Korea, Russia, Somalia, South Sudan, Sudan, Syria, Uganda, Ukraine and Yemen.

The department operates a four-level travel advisory system, with Level 1 indicating that travellers should exercise normal precautions, while Level 2 advises increased caution.

Level 3 advises travellers to reconsider their trips, while Level 4 is the highest category and advises against all travel to the affected destinations.

The department urged Americans to check its travel advisory website for destination-specific information before making travel plans.

Travellers can access the advisories through travel.state.gov/destination. (PUNCH)