"We understand that Pakistani authorities are taking steps to ensure that Omar Sheikh remains in custody while the Supreme Court appeal seeking to reinstate his conviction continues," Acting Attorney General Jeffrey A Rosen said in a statement.

" The separate judicial rulings reversing his conviction and ordering his release are an affront to terrorism victims everywhere," he said.

He said, "We remain grateful for the Pakistani government’s actions to appeal such rulings to ensure that he and his co-defendants are held accountable.  If, however, those efforts do not succeed, the United States stands ready to take custody of Omar Sheikh to stand trial here.  We cannot allow him to evade justice for his role in Daniel Pearl’s abduction and murder."

A Pakistan Court recently ordered to release British-born Ahmed Omar Saeed Sheikh, accused of killing US journalist Daniel Pearl in 2002. 

The Sindh High Court ordered the immediate release of Sheikh declaring his connection with the abduction and murder of US journalist Daniel Pearl null and void.

The provincial high court's ruling overturns a decision by Pakistan's top court that Omar Saeed Sheikh, a key suspect in Pearl's murder, should remain in custody, his lawyer said. Sheikh was acquitted of murder charges earlier this year, but was held while Pearl's family appeals the acquittal.

Sheikh was convicted on charges of luring Pearl to a meeting in Karachi from where he was kidnapped and subsequently murdered.

In 2002, Pearl, who was the South Asia bureau chief for The Wall Street Journal, was abducted and murdered while he was in Pakistan.