The move has been welcomed by tourist board, Discover Tunisia, which described the move as a “huge boost” for the country.
Tunisia was rocked in June 2015 by the devastated Sousse terror attack, in which 30 Britons were killed.
Since then, the FCO has persistently urged caution when travelling to the north African state.
Charter flights from the UK were suspended following the attack, but resumed in February with the return of Thomas Cook. Tui has also since resumed flights to Tunisia.
MORE: Sousse survivor calls on industry to champion FCO travel advice
The FCO on Thursday said it was now no longer advising against all but essential travel to the town of Jendouba, around 120 miles from capital Tunis.
It has also revised down the threat level for some areas of southern Tunisia, including Medenine, Tataouine and Douz.
Tunisia’s key tourist locations on its eastern Mediterranean coast, such Sousse and Hammamet, carry only an FCO advisory notice reminding visitors to read its advice before travelling.
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Posting on Facebook on Thursday (June 14), Discover Tunisia said: “The FCO has changed its travel advice by extending the green areas to travel around safely in Tunisia.
“This news represents a huge boost for Tunisia confidence as a reliable [and] safe destination for tourists.”
Wahida Jaiet, director of the Tunisia National Tourist Office, added: “The change in the FCO travel advice will give a huge boost to confidence in Tunisia. 2018 is the year to rebuild faith and trust in Tunisia.”
