The United States slapped fresh sanctions on Iran's financial sector, targeting 18 Iranian banks in an effort to further shut Iran out of the global banking system as Washington ramps up pressure on Tehran weeks ahead of the U.S. election.

"Amid Covid 19 pandemic, U.S. regime wants to blow up our remaining channels to pay for food & medicine," Zarif said on Twitter. "But conspiring to starve a population is a crime against humanity."

Iranian Central Bank governor Abdolnaser Hemmati dismissed the new sanctions as propaganda linked to U.S. domestic politics.

"Rather than having any economic effect, the American move is for U.S. domestic propaganda and political purposes, and shows the falsity of the human rights and humanitarian claims of U.S. leaders," Hemmati said in a statement posted on the central bank's website.

Foreign Ministry spokesman Saeed Khatibzadeh accused Israeli Prime Minister Benjamin Netanyahu in a tweet of being behind the new sanctions in a move to "lure (U.S. President Donald) Trump into doubling down on inhumane targeting of ordinary Iranians".

(Reporting by Dubai newsroom, Editing by Franklin Paul and Richard Pullin)