U.S. to closely watch China's actions on cyber crime: Obama

WASHINGTON (Reuters) - U.S. President Barack Obama said he warned China's President Xi Jinping that the Asian nation must demonstrate that it is not sponsoring cyber crime and espionage, and that it is enforcing the law against those using the Internet to steal U.S. companies' trade secrets.

"The question now is: are words followed by actions?" he said at a joint press conference with Xi. "And we will be watching carefully to make an assessment as to whether progress has been made in this area."

If China does not follow through, Obama said the United States will use sanctions, traditional law enforcement, and other measures "to go after cyber criminals either retrospectively or prospectively," a warning that the United States will work to prevent future crimes.

(Reporting by Julia Edwards, Jeff Mason and Roberta Rampton; Writing by Lisa Lambert; Editing by Susan Heavey)