noun
joint communique; joint statement
A formal written statement issued jointly by two or more parties, often governments or organizations.
両国は共同文書を発表した。
The two countries issued a joint communique.
共同声明 is a more common term for a joint statement, while 共同文書 emphasizes the written document itself.
Compound of 共同 (joint, cooperative) and 文書 (document, written statement).