China is developing one of the greatest nuclear weapons forces in history while Russia will exploit every opportunity to undermine the U.S. and its allies, according to an annual threat assessment by the U.S. Office of the Director of National Intelligence.

In a stark, declassified 31-page document, the report released late Monday by the House Intelligence Committee says Iran will continue to threaten American interests as it seeks to erode U.S. influence in the Middle East. At the same time, North Korea is committed to expanding its nuclear arsenal and ballistic missile development, according to the assessment.

"In the coming year, the United States and its allies will face an increasingly complex and interconnected global security environment marked by the growing specter of great power competition and conflict, while collective, transnational threats to all nations and actors compete for our attention and finite resources,” according to the document.