Prosecutors have revealed the New York subway bomb suspect wrote on Facebook: "Trump, you failed to protect your nation."

Akayed Ullah has been charged with providing material support to terrorists and using weapons of mass destruction, following a failed suicide bombing in New York on Monday.

Authorities say he set off a bomb underneath Times Square, in a busy passageway connecting a subway and the country's largest bus terminal.

Only Ullah was seriously hurt in the blast, which detonated during the Monday morning rush hour but malfunctioned and resulted in panic and minor injuries for three people.

The moment the New York bomb went off

Law enforcement officials have said that Ullah looked at Islamic State propaganda online before the attempt, and later told investigators he was retaliating against US military aggression.


According to the criminal complaint against him, the 27-year-old said "I did it for the Islamic State" after being taken to hospital with burn injuries to his body and hands.

FBI deputy commissioner John Miller said Ullah, who was originally from Bangladesh, had not been on the agency's radar before Monday.

Donald Trump claimed the bombing highlighted a need for the extreme changes he has proposed to the US immigration system - which he claims is "lax" and "allows far too many dangerous, inadequately vetted people" into the country.

He called on Congress to end chain migration, which allows family members to join relatives who have immigrated to the US, and said those convicted of terror acts "deserve the strongest penalty allowed by law, including the death penalty."

Governor: NY blast caused by 'low-tech' bomb

The suspect's family have said they are "heartbroken" and deeply saddened by the suffering the attack has caused.

In a statement issued through the Council on American-Islamic Relations in New York, they said they were "outraged" by the way law enforcement had responded to the case.

A teenage family member had been pulled from a class and questioned without a guardian or lawyer present, they said.

Bangladeshi authorities have been working to investigate Ullah and have learned that he has a wife and baby in his home country, where he is not thought to have a criminal record.

"A terrorist is a terrorist irrespective of his or her ethnicity or religion, and must be brought to justice," the Bangladeshi government said in a statement.