FBI spokeswoman Lindsay Godwin said the two had been put on the most wanted list for providing support to foreign terrorist organisations.
A third man Raddulan Sahiron, a native of the Philippines, was also put on the list for his involvement in the 1993 kidnapping of an American in the Philippines by the Abu Sayyaf Group.
FBI said Aminullah was linked to the Kashmir-focused Pakistani militant group LeT, which had links with al-Qaeda network.
The agency said he was wanted for providing material support such as currency or financial services to the LeT and for planning terrorist plots.
Aminullah is also wanted for threatening the security of US nationals.
The other prominent terrorist to figure in the new list Shafik Hammami is reportedly a senior leader in al-Qaeda linked al Shabaab in Somalia. Hammami, FBI said, travelled to Somalia in 2006 to join al Shabaab.
The FBI's most wanted list was created in October 2001 in the wake of September 11 attacks and contains 31 people including terror masterminds like the new Al Qaeda chief Ayman al-Zawahiri.