Mohammad Reza Falahzadeh, deputy commander of Iran's Islamic Revolutionary Guard Corps-Qods Force (IRGC-QF), and Ibrahim al-Nashiri, a member of Yemen's Houthi militia, were designated under the sanctions, the Treasury Department said.

The Iranian military has provided weapons and intelligence support to the Houthis that support the group's attacks on international shipping in the Red Sea, the department said in a statement.

The department designated Cap Tees Shipping Co., Ltd, which owns and operates a vessel used to ship Iranian commodities that were sold to support both the Houthis and the IRGC-QF, it said.

Shipping risks have escalated due to repeated Houthi drone and missile strikes in the Red Sea and Bab al-Mandab Strait since November in support of Palestinians in Gaza. U.S. and British forces have responded with several strikes on Houthi facilities but have so far failed to halt the attacks.

On Tuesday, the U.S. also imposed imposed sanctions against two companies that run a vessel that shipped more than $100 million in Iranian commodities to businesses in China on behalf of Iran's defense ministry, the Treasury Department said.

Tehran's defense ministry orchestrated the shipment in January aboard the Panamanian-flagged vessel Kohana, which is owned by Hong Kong-registered Kohana Company Limited and operated by the Marshall Islands-registered Iridescent Co Ltd, the department said in a statement.

Britain also added five new designations under its Iran sanctions regime and one under its Yemen sanctions regime, a government notice showed on Tuesday.

(Reporting by Doina Chiacu; editing by Rami Ayyub)