Iranian President Mahmoud Ahmadinejad should celebrate his birthday this week by freeing two imprisoned American hikers, the State Department said on Twitter Thursday. 

"What a gift that would be," tweeted State Department spokesman Philip Crowley after wishing Ahmadinejad a happy birthday.

"Your 54th year was full of lost opportunities," Crowley added. "Hope in your 55th year you will open Iran to a different relationship with the world." 

Josh Fattal and Shane Bauer, who were arrested while hiking along the Iraqi-Iranian border in July 2009, are imprisoned in Tehran.

Their companion, Sarah Shourd, was released in September on $500,000 bail.