U.S. USAID Administrator Samantha Power told a news conference in Nairobi that the amount was in addition to $65 million that USAID had already provided this year.
She said the war in Ukraine was increasing suffering in Kenya and the rest of the region.
The Kenyan government says 4.1 million people in the East African nation are food insecure, up from 3.8 million in March this year.
Margaret Kobia, a Kenyan minister responsible for public service, gender, senior citizens affairs and special programs, said the government had so far spent 12.6 billion shillings ($106.28 million) to help people affected by drought but had a shortfall of 15 billion shillings.
Kenya, as well as much of east Africa, has suffered repeated droughts that have stopped crops as well as killed livestock, heightening food insecurity in the region.