ㄴ다고 밝히다

announced that…, stated that…

A quoted statement in -ㄴ다고 plus 밝히다 "make known" is how Korean news attributes an official announcement: 피지컬 AI 사업부를 이번에 신설한다고 밝혔습니다, 최대 50%의 관세를 매긴다고 밝혔습니다. All four lines here are business or politics reporting in the formal -습니다 style, and the subject is always an institution — a company, a government, a party. 말하다 is plain "said"; 밝히다 means stating a position publicly and on the record, so it carries weight that 말하다 does not.

Register: formal news reporting