On 22 May 2003, the US adopted Executive Order (E.O.) 13303, which declared a national emergency with respect to Iraq. That E.O. was later amended by (inter alia) E.O. 13315, E.O. 13350 and E.O. 13438, which imposed asset freezes on the “former Iraqi regime, its senior officials and their family members”, as well as those “threatening the peace or stability of Iraq or the Government of Iraq”.
On 18 May 2018, President Donald Trump extended those sanctions for 1 year by continuing the national emergency as declared. White House press release here.