Sky Sports' Kaveh Solhekol relayed the news:
Sanchez is in the final year of his deal at the Emirates Stadium and will leave for free next year if he is not sold or signs a new deal before then.
Per BBC Sport's David Ornstein, Arsenal are only prepared to consider offers for Sanchez that include a player as part-exchange:
Bleacher Report's James McNicholas believes that is the right approach from the Gunners:
Indeed, a transfer fee alone—even a large one—is perhaps not worth the difficulties Arsenal will face by allowing their biggest star to significantly strengthen City, who already appear to be in a strong position to challenge for the Premier League title.
Sterling isn't yet at Sanchez's level, but he'd nevertheless be a strong acquisition who could mitigate the Chilean's departure, and at 22 he has a considerable youth advantage too.
City can afford to part with him if they're getting Sanchez in return—given they already have the likes of Sergio Aguero, Gabriel Jesus, Leroy Sane and Bernardo Silva—but it seems he will not be moving.
Without him, Arsenal may well hold their resolve even if City make another large cash offer.