Rezwan Ferdaus was also charged with attempting to supply materials to al-Qaeda and aid attacks on US soldiers.

The Northeastern University physics graduate is accused of planning to commit "jihad" since early 2010.

Mr Ferdaus was arrested in Boston on September 28 after an undercover investigation by the FBI.

Announcing his arrest, the US Department of Justice described an elaborate operation over a period of months leading up to the arrest of Mr Ferdaus.

Authorities said he designed and supplied undercover operatives with a total of eight mobile phone detonators intended to be used by al-Qaeda operatives to set off bombs in the Middle East.

Also during 2011, Mr Ferdaus began speaking to the agents about his desire to organise an attack on the Pentagon, home of the US military, and the Capitol building in Washington DC, seat of the US Congress.