Prosecutors said Wesam El-Hanafi bought seven watches to sent to militants in Yemen to be used as bomb triggers
A New York man pleaded guilty on Monday to terrorism charges for helping the militant group al-Qaida.
Brooklyn-born Wesam El-Hanafi, 37, pleaded guilty to one count of providing material support to a terrorist group and one count of conspiracy.
Manhattan federal prosecutors, in a plea agreement with the defence, recommended a 20-year prison sentence.
"In July 2009 I participated in a conversation with others in which we discussed seeking out additional contacts within al-Qaida," El-Hanafi told US district judge Kimba Wood.
El-Hanafi was arrested in April 2010, along with Sabirhan Hasanoff, 36, a dual US and Australian citizen who pleaded guilty on 4 June to similar crimes. The men, who were arrested abroad and brought to the United States to face charges, had been under law enforcement surveillance.
Prosecutors have said El-Hanafi bought seven digital Casio watches through Amazon.com to send to militants in Yemen and that the alarms in the watches could be used as bomb triggers. His defence attorney said the watches were gifts to his family.
At a court hearing at the time of his arrest, a federal prosecutor said El-Hanafi had traveled to Yemen in February 2008 to link up with al-Qaida leadership.
Once there, a hood was placed over his head and he was taken to a house where he met with senior members of al-Qaida, to whom he pledged allegiance, the prosecutor said.
In the months before his arrest, El-Hanafi was placed on a US "no-fly list". In February 2010 he contacted US authorities in the United Arab Emirates to find out why he was barred from flying and was arrested shortly afterward.
El-Hanafi will be back in court in October but a sentencing date has not been set due to health problems caused by a blood clot in his leg.