The 23-year-old Argentina international was at City's Carrington training ground this morning having cut short a holiday in his homeland to fly in to finalise contract negotiations and undergo a medical.
Aguero, the son-in-law of Diego Maradona, is currently on leave having been involved in the Copa America.
"Just arrived in Manchester to finalise the details of signing with City," Aguero wrote on Twitter.
"Everything is going very well! I'll tell you more in a while."