Pyongyang, North Korea ? North Korea lashed out Tuesday at ongoing U.S.-South Korean military drills and warned that it could take retaliatory action amid renewed concern that the communist nation may be preparing to test a nuclear bomb.

The North’s latest rhetorical salvo came after President Bush spoke Monday with Chinese President Hu Jintao about how to persuade the North to return to deadlocked international talks on its nuclear weapons program.

The U.S. and South Korea launched the annual joint military exercises on Monday, which the North had previously said would be considered a declaration of war. Some 29,500 U.S. troops remain in South Korea as a legacy of the 1950-53 Korean War that ended in a cease-fire that has never been replaced by a peace treaty.

The U.S. military has said the exercises are defensive in nature and not a provocation.