A "non-decision" from an Iranian cleric on the fate of jailed Pastor Youcef Nadarkhani has delayed his possible execution.

In 2009, the Iranian judiciary sentenced Nadarkhani, 34, to be put to death for refusing to recant his Christian faith.

The court had said it would issue a decision by mid-December after it sought the advice of Supreme Leader Ayatollah Khamenei.

But according to the American Center for Law and Justice, the head of the Iranian judiciary instructed the court to delay its decision for another four months.

The ACLJ said the move appears to be an attempt to give the Islamic Republic's supreme leader more time to weigh his decision.

Last weekend, Secretary of State Hillary Clinton called on Iran to release "all prisoners of conscience immediately and unconditionally, including Pastor Youcef Nadarkhani," after some 200,000 Americans signed a petition on his behalf launched by the ACLJ.