A major U.S. intelligence report released in Washington on January 22 lists Russia, China North Korea and Iran as the "traditional adversaries" of the United States.
The report says Russia's efforts to expand its influence and the modernization of China's military are among the "ever more diverse" threats facing the United States.
The strategic assessment also says "despite its 2015 commitment to a peaceful nuclear program, Iran’s pursuit of more advanced missile and military capabilities and continued support for terrorist groups, militants, and and other U.S. opponents will continue to threaten U.S. interests."
The National Intelligence Strategy report, issued every four years, also warns about potential threats such as North Korea's pursuit of nuclear weapons, the growing cyber capabilities of U.S. adversaries, and global political instability.
As the guiding strategy for 17 U.S. intelligence agencies, the report will drive the strategic direction of the U.S. intelligence community for the next four years.
It says the United States "faces an increasingly complex and uncertain world in which threats are becoming ever more diverse and interconnected."
Director of National Intelligence Dan Coats said in a letter accompanying the report that U.S. intelligence agencies must adapt in order to respond to what he calls a "turbulent and complex" environment.
"We face significant changes in the domestic and global environment," Coats said. "We must be ready to meet the 21st-century challenges and to recognize emerging threats and opportunities."
He said the U.S. intelligence community must improve cooperation between agencies and be more innovative.
Coats also said agencies must do more to increase transparency to raise public trust in their work.
The report does not rank the threats.
But its first section is devoted to the threat posed by "traditional adversaries" who are trying to take advantage of the weakening of the post-World War II international order and increasingly isolationist tendencies in the West.
"Russian efforts to increase its influence and authority are likely to continue and may conflict with U.S. goals and priorities in multiple regions," it says.