The Dervishes are consented to register the promising forward on immediate effect, completing the three spots available for foreigners.

"John signed for Ismaili on Monday," agent Sunny Ruebens told FilGoal.com.

"I prefer not to reveal details of the contract for now, but John is ready to play for Ismaili immediately."

Ruebens declared that the 20-year-old rejected an offer from Ahli Dubai as he is poised to join the Nigeria first team.

"He had an offer from Ahli Dubai, but we thought Ismaili would be better for him," he added.

"Jambo's chances of getting a call from the Nigeria first team would be limited if he joined Ahli, because he won't be able to play before January."

Jambo will be hopeful to join the Super Eagles for next January's African Championship of Nations in Ivory Coast.

The Nigerian had an impressive spell at second division Canal last season, where he hit 13 goals for the Ismailia-based side.