Iran denied on Saturday U.S. accusations that it was involved in planning attacks by Yemen's Tehran-aligned Houthi movement on commercial vessels in the Red Sea, the semi-official Mehr news agency reported.

The repeated denial, issued by Iranian deputy foreign minister Ali Bagheri Kani, came after the White House said Tehran was "deeply involved" in planning the operations and its intelligence was critical to enable the Houthis to target ships.

"The resistance (Houthis) has its own tools of power and acts according to its decisions and capabilities," Bagheri Kani told Mehr.

Iran supports the Houthis but officially denies arming the group, which has seized Yemen's capital Sanaa after ousting the government and now controls large swaths of the country.

The Houthis, who say their attacks are aimed at Israel-linked ships and are in support of Palestinians under siege by Israel in Gaza, have targeted commercial shipping in the Red Sea with drones and missiles, forcing shippers to change course and take longer routes around the southern tip of Africa.