expression, adverb
as soon as possible; at the earliest time
A set phrase used adverbially to express urgency or a request for prompt action. Often used in business or formal requests.
できる限り早くご返事ください。
Please reply as soon as possible.
できる限り早く出発しよう。
Let's depart at the earliest possible time.
A fixed phrase composed of できる (potential form of する, 'to do') + 限り ('limit, as much as') + 早く (adverbial form of 早い, 'early'). Literally 'as early as one can do'.