Iran's new top security chief Mohsen Rezaei has threatened US economic interests and warned countries against joining Washington's drive to tighten pressure on Tehran, days after President Donald Trump announced what he called an 'economic D-Day' against Iran.

"If he [Trump] wants to take certain actions, our response will be an equivalent, earthquake-like retaliation. First, we tell all neighbouring countries and other countries around the world not to enter into an economic war alongside the United States. Any country that partners in creating economic restrictions against us will be considered an enemy.

He said Tehran would first seek talks with countries considering economic restrictions but warned if they failed to comply, they would hit the interests of that country.

Rezaei also threatened American commercial interests if Washington follows through with further economic measures, saying Iran had previously focused its attacks on US military bases.

"Now, if they are going to impose economic sanctions on us, the US has many oil companies and economic interests around Iran and in other places; well, we will hit those."

Trump announced his new economic pressure campaign last week, warning countries and companies against providing Iran with an economic lifeline. US Treasury Secretary Scott Bessent has said Washington intends to impose what he called the "toughest sanctions in history".

Rezaei also argued that US and Israeli attacks on Iranian nuclear facilities had damaged confidence in the global non-proliferation system, saying other governments could conclude that NPT membership and international monitoring offered no protection against military attack.

Rezaei separately said Iran and Oman had agreed on a transit route through the Strait, although negotiations were not complete.

He also warned Washington against increasing its military presence or making what he described as hostile moves around the strait.