尽快
as soon as you like or can
Please return the completed form at your earliest convenience. 请将填好的表格尽快交回。
I would be grateful if you could call me back at your earliest convenience.
There's a letter here from Charles Gordon, asking for a meeting at your earliest convenience.
Please contact me at your earliest convenience so that we may exchange any relevant information.
We look forward to receiving the payment at your earliest convenience.
See also: convenience (BEING EASY)