Palestinian authorities found liable in a high-profile lawsuit over Americans killed in terrorist attacks must pay $10 million in cash—and an additional $1 million monthly payment while the case is on appeal—to secure the hundreds of millions awarded by a jury, a Manhattan federal judge ruled Monday.

In ordering the security payment, Southern District Judge George Daniels said he had given significant thought to a motion filed this month by the U.S. State Department, which intervened through the Department of Justice to argue a high bond could threaten the stability of the region by straining the cash-strapped Palestinians.