The Obama administration has offered up to US$12 million (NZ$14.6m) in rewards for information leading to the location of two Iran-based Al Qaeda leaders.
The US says they're key facilitators in sending extremists to Iraq and Afghanistan.
The State Department says it will provide up to US$7m for information on Muhsin al-Fadhli and US$5m for information on Adel Radi Saqr al-Wahabi al-Harbi.
The announcement early today (NZ time) coincided with new Treasury Department penalties against al-Harbi. Any assets he holds in the US are now blocked and Americans are banned from doing business with him. Al-Fadhli is already subject to such restrictions.