Tajideen, 63, pleaded guilty before a Washington court and faces five years in prison and a forfeiture of $50 million if his deal with prosecutors is accepted.
He was named a Specially Designated Global Terrorist in May 2009 by the Treasury Department over his links to Hizballah.
Tajideen has been detained since extradition to the United States in March 2017 after his arrest overseas, the statement added.
"We are going to keep targeting Hizballah and other terrorist groups and their supporters, and we are going to keep winning," said Acting Attorney General Matthew Whitaker, who hailed the guilty plea.
Hizballah has been a US designated terrorist group since 1997 and fights alongside the regime of Syrian President Bashar al-Assad in the country's civil war.
But in Lebanon it is one of the country's three powerful political factions and was for decades hailed across the Arab world as the most prominent pro-Palestinian resistance group.
Follow us on Twitter: @The_NewArab