The 17-year-old came to prominence as part of the World Cup winning under-17 team.
The Nigerian teenager was named player of the tournament and Arsenal moved quickly to sign him up.
After battling through visa and work permit, the issues appeaar to have been resolved.
On his return to his homeland, Nwakali confirmed he had completed his “dream” move.
“I just came back from London; I have signed a five-year contract with Arsenal.
“So many teams were interested in me, but it has been my dream at a tender age to play for Arsenal.”