“The U.S. will not have all the time in the world,” Rabiei said. “We are waiting for the official announcement of their stance as well as the lifting of sanctions.”

In the meantime, he added that Iran would take a step further away from the nuclear deal by imposing a “restriction” on inspections by the U.N. nuclear watchdog in late February.

In December, Iran’s parliament approved a law under which part of the inspections that the deal had provided for would be suspended in February if European signatories to the 2015 nuclear deal do not offer relief from oil and banking sanctions.

“The window of opportunity will not be open forever, either for the U.S. or the European members of the nuclear deal to fulfill their commitments,” Rabiei added.