Iranian Foreign Minister Abbas Araghchi on Saturday dismissed the impact of recent Western sanctions, imposed over alleged arms exports to Russia, calling them a "failed tool" to influence Tehran's policies.
Britain, France and Germany announced on Tuesday sanctions targeting Iranian air transport, accusing Tehran of delivering ballistic missiles to Russia for use in the Ukraine war.
Iran has repeatedly denied sending any weapons to Russia for use in the Ukraine war, and vowed to respond to the latest in a long string of Western sanctions against Tehran including over its nuclear activities.
The official news agency IRNA quoted Araghchi as saying: "It's surprising that Western countries still do not know that sanctions are a failed tool and that they are unable to impose their agenda on Iran through sanctions."
The top Iranian diplomat called sanctions "a tool of pressure and a tool of confrontation, not a tool of cooperation".
Araghchi added, according to IRNA, that Iran has "always been open to negotiations" and "constructive dialogue" with other countries.
"But the dialogue should be based on mutual respect, not threats and pressure."
Britain called in Iran's envoy in London on Wednesday and warned him that his government would face a "significant response" if it continued to supply Russia with missiles to use in Ukraine.
The United States has also stepped up sanctions on Iran, including on flag carrier Iran Air "for operating or having operated in the transportation sector of the Russian Federation economy," the Treasury Department said on Tuesday.
On Thursday, the Iranian foreign ministry summoned four European ambassadors to protest the sanctions.
Iran has suffered years of crippling Western sanctions, especially after its arch-foe the United States in 2018 unilaterally abandoned a landmark nuclear deal between Tehran and major powers.