Controlling the epidemic is the most pressing task.
Tips
usage
当务之急 is used as a noun phrase, typically as the subject or predicate with 是. It's a very common idiom in both formal writing and spoken Chinese when discussing priorities.
history
This idiom originates from Mencius (《孟子》): 知者无不知也，当务之急 — a wise person knows everything, but prioritizes what's urgent.
