Malik Faisal Akram, 44, from Blackburn, Lancashire, told US Immigration officers he was checking in at an address on Queen s Boulevard, New York, but never turned up.
The White House press secretary was forced to defend the Biden administration amid an onslaught of national security concerns raised by prominent Republican officials.
The Blackburn terrorist, 44, was shot dead in Texas on Saturday night after a 10-hour siege at the Congregation Beth Israel synagogue in Colleyville where he took a rabbi hostage.
Malik Faisal Akram, 44, from Lancashire, staged a ten-hour attack near Dallas and held the rabbi and three others hostage while demanding the release of a terrorist known as Lady Al Qaeda.
Pressure is continuing to grow on security services amid concerns over how Malik Faisal Akfram, from Blackburn, was able to travel to the US despite his criminal convictions and known radical views.