US special envoy for Yemen Tim Lenderking accused Iran of continuing to support the Houthi movement by supplying weapons and drugs. Iran denies arming the Houthis, who seized Yemen's capital Sanaa after the government was toppled and now control large parts of the country.
The conflict is widely seen as a proxy war between Saudi Arabia, which led a military coalition to support Yemen's legitimate government in 2015, and Iran. Saudi Arabia and Iran signed an agreement on March 10 to resume diplomatic relations, ending a seven-year rupture between the countries.