(CNN) -- Pakistani authorities have charged an American being held in Pakistan's tribal region with illegal entry and illegal possession of a weapon, the State Department said Friday.

Juddi Kenan Mohamed was arrested Monday at a checkpoint in the northern district of Mohmand near Peshawar as he was trying to enter the area, said Husain Haqqani, Pakistan's ambassador to the United States.

Mohamed was carrying a U.S. passport and said he was traveling to see a friend in the tribal area near the Afghanistan border, Haqqani said. However, he was detained because all foreigners are required to have a permit to enter such areas.

There is no evidence Mohamed poses a security risk, Haqqani said.

Gordon Duguid, a State Department spokesman, said the U.S. consul general visited Mohamed in Islamabad on Tuesday and is seeking another visit.

The United States is providing "all possible assistance" to Mohamed, including helping him find a lawyer, Duguid said.

Don't Miss Sources: Suspected U.S. strike kills 4 in Pakistan

Citing privacy laws, Duguid could not explain why Mohamed was detained in Pakistan's tribal region, which is largely controlled by Taliban and al Qaeda militants.

Haqqani said Mohamed is believed to hold dual citizenship in America and Pakistan, and also has a Pashtun name. He said Mohamed's mother has described the situation as a misunderstanding, and Pakistani security services are investigating.

Pakistan's military is waging a bloody battle against Taliban and al Qaeda militants inside the lawless region along the border with Afghanistan. U.S. forces based in Afghanistan have also targeted militants in Pakistan's tribal region.

Last month, the U.S. military sent ground forces into South Waziristan -- also a tribal area -- without Islamabad's permission, prompting an angry response from Islamabad over reported civilian casualties.

And media reports have said that several months ago, President Bush authorized U.S. special forces to carry out ground assaults inside Pakistan without seeking Islamabad's permission.

All About Pakistan