The first Guantanamo Bay detainee to be taken to the United States for trial has pleaded not guilty to two embassy bombings.

Ahmed Ghailani entered the plea last night in federal court in Manhattan.

“With his appearance in federal court today, Ahmed Ghailani is being held accountable for his alleged role in the bombing of US Embassies in Tanzania and Kenya and the murder of 224 people,” Attorney General Eric Holder said.

“The Justice Department has a long history of securely detaining and successfully prosecuting terror suspects through the criminal justice system, and we will bring that experience to bear in seeking justice in this case.”

Ghailani’s trial will be an important test case for the Obama administration’s plan to close Guantanamo in seven months and bring some of the suspects to trial.

Ghailani was charged in 1998 for the al Qaida bombings of US embassies in Kenya and Tanzania, attacks which killed more than 224 people.

US officials say Ghailani began his terrorist career on a bicycle delivering bomb parts and rose through the al Qaida ranks to become a bodyguard to Osama bin Laden.

Ghailani, a Tanzanian, was in his twenties when prosecutors say he helped terrorists build one of the bombs that destroyed US embassies in East Africa in 1998.

He left Africa just before the bombings, according to investigators.

He then worked for al Qaida as a document forger, trainer at a terror camp and bodyguard to bin Laden.

He was categorised as a high-value detainee by US authorities after he was captured in Pakistan in 2004 and was transferred to the detention centre at the US naval base in Cuba two years later.

Since his capture, Ghailani has denied knowing the TNT and oxygen tanks he delivered would be used to make a bomb. He also denied buying a vehicle used in one of the attacks, saying he could not drive.

Now, the Obama administration is trying to put him into the US criminal justice system, despite claims by Republican critics that doing so would endanger American lives. Some politicians have opposed taking any Guantanamo detainees to the US for trial, even in heavily guarded settings. Last month, President Barack Obama said that preventing Ghailani from coming to US soil “would prevent his trial and conviction. And after over a decade, it is time to finally see that justice is served, and that is what we intend to do”.

Relatives of those killed in the embassy attacks have supported the decision to bring Ghailani to the US for trial. Many of those relatives say that since the 2001 terror attacks, the earlier victims of al-Qaida have been forgotten.

Yet the president faces pressure from across the political spectrum on his plan to close the detention centre. Democrats have said they want to see the president’s plan for closing the base before approving money to finance it, and Republicans are fighting to keep Guantanamo open.