TEHRAN — Iran's foreign ministry on Thursday rejected the latest round of US sanctions and said it would not return to nuclear negotiations under what it called economic coercion, hardening a standoff with Washington. The statement followed sanctions announced earlier this week.

US President Donald Trump's administration announced fresh measures on Monday targeting Iran's oil exports and financial networks, describing the campaign as maximum economic pressure. A spokesperson for the Iranian foreign ministry, Esmaeil Baghaei, condemned the move as illegal and a violation of diplomacy.

The sanctions target companies and vessels accused of helping Iran evade restrictions on crude sales, primarily to buyers in Asia. Iranian officials said the measures would fail to change Tehran's policy and vowed to continue exporting oil through alternative channels.

The exchange deepened tensions that have persisted since the collapse of indirect talks earlier in the year. European governments, including France, Germany and the United Kingdom, have urged both sides to return to dialogue over Iran's uranium enrichment programme.

Analysts at the International Crisis Group have warned that continued escalation raises the risk of confrontation in the Gulf, where Iran has previously threatened shipping. The United Nations nuclear watchdog has repeatedly said its inspectors face restricted access to Iranian facilities.

"Pressure and sanctions have never worked against the Iranian nation and never will," Baghaei said, according to state media.