An appeals court has blocked US President Donald Trump's administration from resuming the death penalty for crimes at the federal level.

Key points: Federal executions have been halted since 2003 due to a legal battle

Federal executions have been halted since 2003 due to a legal battle But since July, the US Justice Department has attempted to resume executions

But since July, the US Justice Department has attempted to resume executions Executions for five inmates had been scheduled for this month, but have been delayed

The US Court of Appeals for the District of Columbia Circuit turned down a request from the Justice Department to overturn a judge's decision that temporarily stalled plans for executing four convicted murderers. The first was scheduled to die on December 9.

US District Judge Tanya Chutkan last month issued a stay to the planned executions until a long-running legal challenge to the department's lethal injection protocol could be resolved.

The appeals court found that the administration had "not satisfied the stringent requirements" to block the lower court's ruling.

Attorney-General William Barr, appointed by Mr Trump earlier this year, announced in July plans to resume executions of people sentenced to death in federal cases.

Mr Barr at the time said his department upholds the rule of law and owed it to crime victims and their families to carry out sentences imposed under the American criminal justice system.

Shawn Nolan, a lawyer for the men facing federal execution, welcomed the latest court's ruling.

"The courts have made clear that the government cannot rush executions in order to avoid judicial review of the legality and constitutionality of its new execution procedure," Mr Nolan said.

A Justice Department spokeswoman did not offer any immediate comment on the ruling.

Federal executions blocked by court battle

The last federal execution in the United States took place in 2003. Since then, protracted litigation over the drugs historically used in lethal injection executions prevented the government from continuing the practice.

Lawsuits challenging federal lethal injections were first filed in 2005. Under Mr Trump's predecessor Barack Obama, the Justice Department abandoned its previous three-drug protocol due to a shortage of one of them, an anaesthetic called sodium thiopental.

The legal fight fell dormant during Mr Obama's tenure but was revived in July, when Mr Barr scheduled the executions of five inmates for December and January.

He also unveiled a new protocol that involved using a single drug, pentobarbital, for lethal injections.

Daniel Lewis Lee, a white supremacist convicted in Arkansas for murdering a family of three, was scheduled to be the first of the inmates to be executed, at a federal prison in Indiana on December 9.

Four of the five inmates have joined the 2005 lawsuit.

A fifth inmate who Mr Barr had ordered executed, Lezmond Mitchell, won a stay of execution from another federal appeals court in October.

Most executions in the United States have been carried out by individual states, though an increasing number of them have stopped using the death penalty.

Reuters