The Palestinian Authority (PA) and Palestine Liberation Organization (PLO) was considered liable - by a US jury in February - for the six attacks on Americans in Israel between 2002 and 2004, where 33 people were killed and more than 390 others were wounded.
The American administration said on Tuesday that it had intervened in the case of Israel attacks, where Americans were killed and injured, arguing that a high bond could compromise the Palestinians' financial stability.
More than $218 million were awarded for the families in damages, which was automatically tripled to about $650 million, according to the regulations outlined in the US anti-terrorism act.
According to deputy spokesman Mark Toner, the US State Department said it had filed a Statement of Interest - not on behalf of either party - but to express concerns over the possible bond amount that could be issued in the case,.
The bond amount would be required for the Palestinian Authority to appeal the decision.
"US concerns about the harms that could arise if the ability of the Palestinian Authority (PA) to operate as a governmental authority is severely compromised," said Toner.
"Critical US national security and foreign policy interests should be considered, while acknowledging victim compensation was important,” he added.
It pointed to "US government interests in supporting the rights of victims of terrorism to vindicate their interests in federal court and to receive just compensation for their injuries," Toner said.
The 12-member jury decided unanimously that the PA and PLO were liable on 25 separate counts connected to the attacks.
The bombings and shootings were carried out by Hamas and the Al-Aqsa Martyrs Brigades - blacklisted as terrorist organizations in the United States - during the second Palestinian uprising against Israel.
According to reports, Palestinian officials have said they would appeal the verdict, and their lawyers asked that a bond be waived. The plaintiff’s lawyers seek to have the defendants post a bond of $30 million per month.
"Senior U.S. officials have made clear to other governments that if the PA were to collapse, we would be faced with a crisis that would not only impact the security of Israelis and Palestinians, but would potentially have ripple effects elsewhere in the region," Deputy Secretary of State Anthony Blinken reportedly said according to Associated Press.