Prosecutors in California have charged a man of Pakistani descent with "intending to wage jihad", or holy war, in the United States.
Hamid Hayat, 23, faces one count of providing material support to terrorists and two of lying to the FBI.
The FBI says that during interviews, Mr Hayat admitted being trained in an al-Qaeda camp in Pakistan and that he came to the US to carry out jihad.
His lawyer says no evidence has been offered to back up such claims.
The charge sheet filed in Sacramento alleges Mr Hayat provided support for terrorist acts between March 2003 and June 2005.
The charges carry a maximum term of 31 years in prison.
He was arrested in June in the town of Lodi, 60km (38 miles) from Sacramento.
The indictment said Mr Hayat attended a camp in Pakistan to be trained in "physical fitness, firearms, and means to wage jihad" which he would carry out "upon receipt of orders from other individuals".
Prosecutors said Mr Hayat told an FBI informant he "understood the nature and structure of various known Pakistani terrorist groups and that he had detailed knowledge regarding the mechanics of attending a jihadi camp".
But Mr Hayat's lawyer, Wazhma Mojaddidi, said no evidence had been offered that Mr Hayat had attended the camp.
Relatives have also denied he has been involved in any kind of terrorism.
Prosecutors are still unsure what activities were intended for Lodi but lawyer McGregor Scott said: "Whatever was taking shape in Lodi isn't going to happen now."
Two Islamic leaders, Shabbir Ahmed and Muhammad Adil Khan, were deported as a result of the investigation.
At an immigration hearing last month, an FBI agent said Mr Khan had received orders from a Taleban commander linked to al-Qaeda leader Osama Bin Laden and passed them to Mr Ahmed.
The agent said Mr Hayat was to take orders from Mr Ahmed.
Mr Hayat's father, Umer, 47, was arrested at the same time as his son and faces charges of lying to the FBI.
Father and son are to appear before a Sacramento court on Friday.
The US has launched numerous terrorism prosecutions since the September 2001 attack on the World Trade Centre, although many of these cases have fizzled out.