The 17-year-old has had an outstanding season for the Championship side, scoring 15 goals and providing six assists in 46 league appearances.
Sessegnon received his first call-up to the Under-21 side in March but Jokanovic believes he should be included in Gareth Southgate's 23-man squad for the World Cup.
"He has a really bright future in front of him, not only for Fulham but probably for England in the future or even immediately," the Fulham boss said although he understands the risk of putting too much pressure on him too soon.
"Ryan needs the help from people around him and this kid doesn't need any pressure. He's only 17 and to talk about our possibilities on the back of one kid is not right.
"He's shown many times that he is a great lad, great footballer and great worker. We trust he'll be at his best level.
Southgate will reveal his provisional squad for this summer's tournament on Wednesday.