Today's statement from the British, US and Libyan governments follows an interview ITV News did earlier this week with the justice minister from Libya, in which he said he was now willing to cooperate with police in the US and UK.
The Foreign Office has now welcomed that development and said that it looks forward to visiting Libya in the new year and to getting access to information and witnesses to progress their investigation.
Scotland's Lord Advocate has previously said there are still people out there with blood on their hands for this atrocity.
More top news
A 93-year-old Second World War veteran has flown over 10,000 miles to be reunited with his wartime sweetheart more than 70 years on.
The Republican presidential candidate is known for making some "interesting" comments - but can you guess who made these?
Twitter has announced changes to its timeline which will mean you see the "most important" tweets first.