Iran's parliament passed a bill on Tuesday designating all US forces "terrorists" over the killing of a top Iranian military commander in a US strike last week.
Qasem Soleimani, the popular head of the Revolutionary Guards' foreign operations arm, was killed in a US drone strike outside Baghdad airport on Friday, ratcheting up tensions between the arch-foes.
Under the newly adopted bill, all US forces and employees of the Pentagon and affiliated organisations, agents and commanders and those who ordered the "martyrdom" of Soleimani were designated as "terrorists".
"Any aid to these forces, including military, intelligence, financial, technical, service or logistical, will be considered as cooperation in a terrorist act," parliament said.
Lawmakers also voted to bolster by 200 million euros the coffers of the Quds Force — the foreign operations arm of Iran's Revolutionary Guards that was headed by Soleimani.
The bill was an amended version of a law adopted in April last year that declared the United States a "state sponsor of terrorism" and its forces in the region "terror groups".
Iran's top security body, the Supreme National Security Council, said that blackisting came after the US designated Iran's Revolutionary Guards a "terrorist organisation".