It is necessary.
Sore wa hitsuyō da.
that (indicating an item or person near the listener, the action of the listener, or something on their mind); it; that time; then; there (indicating a place near the listener); you
topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis
necessary; needed; essential; indispensable; necessity; need; requirement
be; is; indicates past or completed action; indicates light imperative