Among the countries on the list are Afghanistan, parts of the Middle East, and regions in Africa.
Most recently, travel advice for Middle Eastern countries has been updated due to the ongoing conflict between Israel and Lebanon.
FCDO’s warning now reads: “A ceasefire in the conflict between Israel and Lebanese Hizballah came into force on 27 November, however, the security environment remains unpredictable.
“Military activity, including airstrikes, cannot be ruled out. Tensions remain high, and the situation could deteriorate with little warning.
“The closure or disruption of roads and exit routes at short notice could affect your ability to leave the country. Do not rely on the FCDO being able to evacuate you in an emergency.
“The security situation presents a range of serious risks to British Nationals in Lebanon, including the following.”