Three Iranian-Americans arrived in Germany after leaving Tehran on Sunday in a prisoner swap that followed the lifting of most international sanctions on Iran under a deal U.S. President Barack Obama said cut off Tehran's path to a nuclear bomb.
In a sign of sustained readiness to track Iranian compliance with remaining United Nations curbs, the United States imposed fresh sanctions on 11 companies and individuals for supplying Iran's ballistic missile program.
The Obama administration had delayed the step for more than two weeks during tense negotiations to free five American prisoners, according to people familiar with the matter.
Iran conducted a precision-guided ballistic missile test last October, violating a U.N. ban.
Speaking after the released Americans had left Iran, Obama said Iran now would not "get its hands on a nuclear bomb" and the planet would be more secure.