"The two leaders affirmed the need to maintain human control over the decision to use nuclear weapons," the White House said in a statement.
But it marks a first-of-its-kind step between the two countries in the discussion of two issues on which progress has been elusive: nuclear arms and artificial intelligence.
Washington has been pushing Beijing for months to break a longstanding resistance to nuclear arms talks.
Formal nuclear arms control negotiations have not been expected any time soon, despite U.S. concerns about China's rapid nuclear weapons build-up, even though semi-official exchanges have resumed.
The U.S. defense department estimated last year that Beijing has 500 operational nuclear warheads and will probably field more than 1,000 by 2030.
Persons:
Joe Biden, Xi Jinping, Biden
Organizations:
Economic Cooperation, White, U.S, United, Pentagon
Locations:
Asia, Lima , Peru, Washington, Beijing, China, United States, Geneva, U.S, Russia, North Korea