Russia's Defence Ministry has said the wreckage of the military plane that crashed into the Black Sea on Christmas Day - killing all 92 people on board - shows no signs of damage from an explosion or fire, Russian media reported.
More than 3,000 people have been involved in the search for victims' bodies and aircraft debris. Two black boxes have since been recovered.
A pilot error or a technical fault is likely to be the cause of Sunday's plane crash, the Russian transport minister said on Monday.
Maxim Sokolov told television reporters that terrorism was not suspected.
He reiterated comments from Sunday afternoon in which he said an "entire spectrum" of possible reasons is being considered for the Tu-154 crash.
But several experts noted factors that could suggest a terror attack, such as the crew's failure to report any malfunction and the fact that plane debris was scattered over a wide area.
The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.