WASHINGTON (REUTERS) - A US Army soldier was arrested on Tuesday (Jan 19) for allegedly trying to help Islamic State in Iraq and Syria (ISIS) fighters attack American troops and targets in New York, including the 9/11 Memorial.

Cole James Bridges - who is 20 and from the state of Ohio - faces federal terrorism charges, United States prosecutors said in a statement.

Bridges - a private based at Fort Stewart, Georgia - began researching extremist ideology and expressing support for the Islamic State on social media shortly after joining the army in September 2019, prosecutors say.

In October 2020, they claim that he started communicating online with an undercover FBI agent posing as an IS supporter who claimed to be in contact with ISIS fighters in the Middle East.

"During these communications, Bridges expressed his frustration with the US military and his desire to aid ISIS," said the statement issued by the Southern District of New York.

"Bridges then provided training and guidance to purported ISIS fighters who were planning attacks, including advice about potential targets in New York City, such as the 9/11 Memorial."

He is accused of later providing information about how to attack US forces in the Middle East, including by providing "specific military maneuvers."

This month, Bridges sent the agent a video of himself in body armour standing in front of an ISIS flag, the prosecutors added.

"Bridges betrayed our country and his unit when he plotted with someone he believed was an ISIS sympathizer to help ISIS attack and kill US soldiers in the Middle East," said William Sweeney, an official at the FBI's New York office.

Bridges has been charged with attempting to provide material support to a designated foreign terrorist organisation and attempting to murder US military service members.

The two counts carry up to 20 years in prison each.