A spike in oil prices over recent days amid a resumption of fighting, however, threatens to push gas prices higher, erasing some of the relief delivered last month.
The move would be a first for a sitting president.
Congressional Democrats warn in a study out Friday, the administration's import taxes will cost American households an average of $2,512 in 2026, up 44% from $1,745 in tariff costs last year.
President Trump is dismissing skyrocketing gas prices as Americans start to feel the economic ripple effects of his war with Iran.
The Dow Jones Industrial Average closed down more than 400 points on Tuesday as the U.S.-Israeli war with Iran prompted a selloff.
"These tariffs were nothing more than an illegal cash grab... Every dollar unlawfully taken must be refunded immediately - with interest. Cough up!" Newsom wrote.