We need to carefully discuss the trade deficit.

Literal

Trade deficit [about-について] cautious-に discuss must.

貿易赤字 ('trade deficit') — 貿易 (trade) + 赤字 (red ink / deficit). 協議する ('to confer, to discuss'). 慎重に is the に-adverbial form of 慎重 ('prudent, cautious'). ~なければならない is the standard obligation form. Subject is omitted — understood as 'we' or 'they.'