North Korea launched multiple ballistic missiles into its western waters on Monday, hours after South Korea and the United States commenced their largest annual military exercises. South Korea's Joint Chiefs of Staff said the missile launches originated from the North's southwestern Hwanghae province and landed in the Yellow Sea west of the Korean Peninsula.

North Korea launched several ballistic missiles toward the Yellow Sea on Monday afternoon, Seoul's military said, on the first day of a large-scale joint U.S-South Korea military exercise on the Peninsula.

North Korea has issued a sharp rebuke over the major military exercise being carried out by the U.S. and its South Korean ally, labeling the training a "war rehearsal." Newsweek reached out to the Pentagon and the South Korean embassy in the U.

The White House said Tuesday the South Korea-U.S. alliance is "ironclad," as tensions flared anew following North Korea's first ballistic missile test this week since the Trump administration took office in January.