North Korea’s foreign ministry condemned a U.S. decision to approve the sale of advanced air-to-air missiles and related equipment to South Korea, warning the move would worsen tensions on the Korean peninsula, state media KCNA said on Saturday.

The ministry’s director-general for external policy said in a statement carried by KCNA that military cooperation between Washington and Seoul was being “systematically strengthened” despite what it called international concern over rising tensions in and around the peninsula.

The official cited the U.S. State Department’s approval of a nearly $300 million foreign military sale of advanced air-to-air missiles and related equipment to South Korea as the latest example.

“U.S. arms exports are war exports,” the official said, adding that North Korea would continue strengthening its self-defensive deterrent to maintain the regional balance of power.

North Korea routinely criticizes U.S.-South Korea military cooperation as preparation for war.

(Reporting by Joyce Lee; Editing by Sanjeev Miglani)