The US government says it is considering redesignating the Houthi insurgents in Yemen as a terrorist organization after they violated international law by hijacking a cargo ship in the Red Sea.

White House National Security Council spokesperson John Kirby revealed the development at a news conference on Tuesday.

The Houthis seized the British-owned Galaxy Leader on Sunday while it was sailing near Yemen on the southern tip of the Arabian Peninsula. The ship is operated by Nippon Yusen, a Japanese firm also known as NYK Line.

The Houthis say the ship is an Israeli ship and that they will continue to target ships owned by or related to Israel.

Kirby called the seizure of the vessel a "flagrant violation of international law."

He said the Houthis should release the ship "immediately as well as the crew, and unconditionally."

He explained that in light of the recent targeting of civilians by the Houthis and now the piracy of a ship in international waters, the US has "begun a review of potential terrorist designations."

Kirby also said, "Iran is complicit due to material support and encouragement of the forces" that conducted the seizure, and called its behavior "absolutely unacceptable."

The US government under former President Donald Trump designated the Houthis as a terrorist organization in January 2021.

President Joe Biden's administration revoked the designation the following month, saying it could exacerbate the humanitarian crisis in Yemen.