While he did not specify who they were, the families are likely to be those of two US service members and two Pentagon personnel who died last week in a blast in the Syrian city of Manbij.
"Will be leaving for Dover to be with the families of 4 very special people who lost their lives in service to our Country!" Trump tweeted.
The air base houses a mortuary where remains of US troops who fell overseas are flown for what is known as a dignified transfer. Personnel of the base helps the bereaved families with the final preparations for the burial.