FILE - The Treasury Building is viewed in Washington, May 4, 2021. AP
The new sanctions target individuals based in Gaza and elsewhere, including Sudan, Turkey, Algeria and Qatar, the US agency said in a statement.
"The United States is taking swift and decisive action to target Hamas's financiers and facilitators following its brutal and unconscionable massacre of Israeli civilians, including children," said Treasury Secretary Janet Yellen in a statement.
The sanctions come as President Joe Biden visits Israel on Wednesday.
"The U.S. Treasury has a long history of effectively disrupting terror finance and we will not hesitate to use our tools against Hamas," Yellen added.
She said that Washington will "continue to take all steps necessary" to deny Hamas the ability to raise funds for carrying out "atrocities."
The US has previously designated Hamas as a terrorist organization.
To date, the Treasury said it has taken aim at nearly 1,000 individuals and entities connected to terrorism and terrorist financing by the Iranian regime and proxies including Hamas and Hezbollah.
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