A US couple was charged on Thursday (April 1) with support for a terror group after trying to board a Yemen-bound ship to join the ISIS militant group, the Justice Department said.

James Bradley, 20, of New York and Arwa Muthana, 29, from Alabama were stopped on Wednesday as they stepped onto the gangplank of a cargo ship in Newark, New Jersey.

The Justice Department said that Bradley had expressed violent extremist views since at least 2019, and in contacts with an undercover law enforcement agency last year repeatedly said he believed in the ISIS (Islamic State in Iraq and Syria) group.

He also told the undercover agent he was willing to carry out an attack against a US target, including possibly the US Military Academy at West Point.

Bradley had already drawn the FBI's attention after a friend of his was arrested in 2019 planning to travel to Afghanistan to join the Taleban, according to a court filing.

Since then, Bradley "has continued to express his desire to carry out violence in support of radical Islamic ideology, directed his support and allegiance to ISIS, and attempted to travel overseas to join and fight for ISIS", the FBI said.

Bradley also shared ISIS propaganda with the undercover agent, and they discussed his various options for joining extremist groups or launching an attack in the United States.

Ultimately, Bradley decided to head to Yemen to link up with the ISIS with Muthana, a woman he married in January this year.

"If I don't find them I just keep going to Somalia," he told the agent, referring to the East African country where the violent, Al-Qaeda-linked Al Shabaab extremist group menaces the government.

The case demonstrated thatextremist groups still exert a pull on some peoplein the US, even after the ISIS wasdefeated by US and allied troops in its home basein Iraq and Syria.

"The threat of terrorism at home and abroad remains," said Assistant Attorney-General John Demers.

The department "is committed to holding accountable those who would provide material support to foreign terrorist organisations", he said.

Both Bradley and Muthana face up to 20 years in prison on the charge of conspiring to provide material support to a foreign terrorist organisation. (AFP)

*File:The case demonstrated that extremist groups still exert a pull on some people in the US