Apparently there's a blacklist of countries and a red list with varying degrees of severity. https://www.msn.com/en-gb/travel/news/the-24-countries-uk-s-foreign-office-says-tourists-simply-must-not-visit/ar-BB1qmfEA?ocid=msedgntp&pc=U531&cvid=2af91e350dd142228acf11b55c3267f0&ei=9
This other list suprises me Steve, Thailand Indian and Mexico? Why are these Countries on this list do you think?
In addition to the blacklist, there is also a red list where travel should be avoided 'unless absolutely essential'.
The list of 42 countries includes all or parts of Algeria, Angola, Armenia, Azerbaijan, Bangladesh, Benin, Burundi, Cameroon, Colombia, Democratic Republic of the Congo, Djibouti, Ecuador, Egypt, Eritrea, Ethiopia, Georgia, India, Indonesia, Ivory Coast, Jordan, Kenya, Kosovo, Laos, Malaysia, Mauritania, Mexico, Moldova, Mozambique, Myanmar(Burma), Nigeria, Pakistan, Papua New Guinea, Philippines, Republic of Congo, Saudi Arabia, Tanzania, Thailand, Togo, Tunisia, Turkey, Uzbekistan, Western Sahara.