"No, but I can't take the chance that it won't," he said, explaining why the Pentagon has strengthened missile defenses and made other decisions to combat the potential threat.
Dempsey said the US has been preparing for further provocations or action, "considering the risk that they may choose to do something" on one of two nationally important anniversaries in April — the birth of North Korean founder Kim Il Sung and the creation of the North Korean army.
US Gen. James Thurman, the commander of the 28,000 American troops in South Korea, will stay in Seoul as "a prudent measure" rather than travel to Washington to appear this coming week before congressional committees, Army Col. Amy Hannah said in an email Sunday to the AP.
Thurman has asked the Senate Armed Services Committee, the House Armed Services Committee, and the House Appropriations subcommittee on defense to excuse his absence until he can testify at a later date.
Dempsey said he had consulted with Thurman about the rising tensions on the Korean peninsula.
Dempsey said both Thurman and South Korea's Joint Chiefs of Staff chairman, Gen. Jung Seung-jo, decided it would be best for them to remain in Seoul rather than come to Washington. The Korean general had planned to meet with Dempsey, the US Joint Chiefs of Staff chairman, in mid-April for regular talks.