The announcement was made by U.S. Attorney for the Southern District of New York Michael Garcia.
The deal is linked to the case of a U.S. businessman who was charged with bribery and fraud by U.S. prosecutors for allegedly diverting millions of dollars from oil companies to three senior Kazakh officials.
AP reports that the funds have been frozen in Swiss bank accounts at the request of the United States.
U.S. prosecutors say the Kazakh government has not acknowledged that the bribery allegations are true, but has agreed that the $84 million can be paid into three funds to benefit the country.
A statement from the U.S. Attorney's office said one fund will benefit poor Kazakh children, a second fund will finance a five-year program to improve public financial management in Kazakhstan, and a third fund will seek to promote transparency in the Kazakh oil, gas, and mining industries.