Two Yemeni nationals were charged with providing material support to al-Qaeda and with conspiring to kill U.S. citizens abroad, according to court documents unsealed on Tuesday.
The Justice Department said that Saddiq al-Abbadi, and Ali Alvi were arrested in Saudi Arabia before being expelled to the U.S.
Alvi's initial court appearance was held Sunday in New York. Abbadi is scheduled for later on Tuesday.
The duo are accused of being members of al-Qaeda who fought American forces in Afghanistan. Abbadi is accused of leading a battle against U.S. forces in Afghanistan in May 2008 that killed one U.S. Army Ranger and seriously wounded several others.
Abbadi is also accused of combatting U.S. forces in Iraq from 2003-2007.
In or around March 2008, Alvi and Abbadi helped an American citizen join al-Qaeda while training and fighting with the terror group in Pakistan's northwest tribal areas, the criminal complaint said.
"The arrest and prosecution of these two individuals, who allegedly directly supported the mission of a designated terrorist organization, is a major step in the international cooperation to combat terrorism," said FBI Assistant Director in Charge Andrew McCabe.
The complaint was originally filed in 2009, but unsealed Tuesday.
Abbadi and Alvi face maximum life sentences if convicted.