Top Rank vice president Carl Moretti said he was hopeful that the fight will be finalised soon but couldn't offer any guarantees.
"It's a fight we're working on and it's a fight we'd like to do but there are a lot of moving parts," Moretti told ESPN.
"Sometimes they get made and sometimes they don't."
It would be Parker's first fight in the US since his TKO victory against Keith Thompson early in his career in 2014.
Jennings (23-2, 13 KOs) is coming off four straight wins, his only two losses coming in title fights against Wladimir Klitschko and Luis Ortiz.
The 33-year-old American will be a stern challenge for Parker, with both fighters looking to fight their way towards another shot at the title.