China has launched a series of ballistic missiles, including an apparent “carrier killer” weapon, into the disputed South China Sea as part of integrated military exercises apparently simulating a strike on U.S. warships in a warning to the United States.

The launches on Wednesday came as Washington blacklisted 24 Chinese companies and targeted individuals it said were part of construction and military activities in the South China Sea — the first such sanctions against Beijing over the strategic waterway and a dramatic escalation of the U.S. offensive against China’s actions there.

They also came as the U.S. neared the end of its annual RIMPAC military drills in Hawaii, the world’s largest maritime exercise with 10 navies represented from regional allies and partners, including Japan.