David Cameron spoke to the President of Egypt on 3 November to offer his condolences over the Russian plane crash.
A Downing Street spokesperson said:
The Prime Minister called President Sisi of Egypt earlier this evening to offer his condolences over the Russian plane crash.
They agreed it was important not to pre-judge the investigation, but noted that there was still uncertainty about the cause of the crash and agreed it would be prudent to ensure the tightest possible security arrangements at Sharm el-Sheikh airport as a precautionary measure.
The Prime Minister said he looked forward to welcoming President Sisi to Downing Street on Thursday when they could talk further about the ongoing investigation and security co-operation between both countries.