The men were arrested on suspicion of trying to contact militant groups
Five young Americans held in Pakistan on suspicion of plotting attacks have been indicted on terrorism charges, their lawyer has said.
The five men, aged 18 to 25, denied the charges at a court in a jail in the eastern city of Sargodha.
They were arrested in the city in December on suspicion of trying to contact al-Qaeda-linked groups.
The five face life imprisonment if found guilty. Pakistan earlier barred their deportation to the US.
The men have claimed they were tortured in custody, and that US officials directed the abuse, but prison officials have denied the accusations.
The US embassy in Islamabad, which has also dismissed the allegations, confirmed that an American consular official attended Wednesday's hearing.
Journalists were not allowed in, but afterwards defence lawyer Shahid Kamal said "charges have been laid against all the accused".
"All these charges are terrorism related. The offences are punishable by life imprisonment. All the accused unanimously rejected them," AFP news agency quoted him as saying.
A second defence lawyer, Hasan Dastagir, told Associated Press: "My clients were in good shape and high spirits."
He said the next hearing would be on 31 March and that prosecutors would produce more than 20 witnesses.
Mr Dastagir said the defence would present evidence of the men's community service in the US, as well as witnesses from there.
Charges against the five young Muslims include "planning to carry out attacks against Pakistan and its allied countries, possessing jihadi literature and making monetary contribution to banned organisations," Nadim Akram Cheema, a government prosecutor, told the BBC Urdu service.
The men disappeared from the US state of Virginia in November.
Their families reported them missing after finding a farewell video message, which is said to have shown scenes of war and calls for Muslims to be defended.
Investigators have said the men were planning to travel to Afghanistan to fight alongside the Taliban.
But the accused have denied any links to al-Qaeda and insist they wanted to go to Afghanistan for charity work.
Two of them are Pakistani-Americans, while the remaining three are said to be of Eritrean, Ethiopian and Egyptian origin. All of them have US passports.