The Treasury Department announced new sanctions on key members of Hamas, as part of a “continuous effort by the United States to root out Hamas’s sources of revenue in the West Bank and Gaza and across the region.”

“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,” Treasury Secretary Janet Yellen said in a statement.

The sanctions target six individuals associated with Hamas’ secret investment portfolio, two senior Hamas officials, and a Gaza-based virtual currency exchange, along with the operator of that exchange.

This is part of a “broad campaign” that is being done with American allies and partners over the coming months that will involve sanctions and “other tools.”

“What we’re doing today is we’re cutting them off from access to their money,” a senior administration official said on a call with reporters Wednesday morning. “It’ll mean that they have fewer resources to pay their fighters to buy the weapons to support their destabilizing activities.”

“Our goal was to make sure that we cut them off from as many sources as possible, make it as hard for them as possible to continue their destabilizing activities in the region,” they added.

To date, the Treasury Department says it has targeted nearly 1,000 individuals and entities connected to terrorism and terrorist financing by the Iranian regime and its proxies, including Hamas, Hezbollah and others.

-ABC News’ Justin Gomez and Elizabeth Schulze and Sarah Kolinovsky