The United States pledged an additional $2.5 billion in emergency assistance and medium- to long-term food security assistance for resilient African food systems and supply markets, the White House said in a statement.
"We're facing a global food crisis, and nowhere is it felt more keenly than on the African continent," Biden said on the last day of a three-day summit in Washington with African leaders from 49 countries and the African Union.
"Today, famine once more stalks the Horn of Africa. High food prices and high trade barriers are taking a toll on the lives and livelihoods of millions of people across the continent."
The United States and African Union on Thursday also announced a strategic partnership to accelerate their work toward food security in the region and laid out several goals, according to a separate statement from the White House.
The short-term goals for the partnership included identifying means for Africa to secure more diverse and resilient sources of grain and fertilizer supply to meet its immediate needs and providing humanitarian assistance.
Among the medium- and long-term goals were exploring ways to improve Africa's access to global markets, increasing reliable and sustainable access to fertilizers and their inputs and diversifying the production of agricultural commodities.
Food insecurity has worsened in much of Africa in recent years, aggravated by a pandemic-provoked economic downturn, rising debt levels and, more recently, the fallout from Russia's invasion of Ukraine, which is partly responsible for food, fuel and fertilizer price spikes.
The crisis has been amplified by protracted armed conflicts and the impacts of climate change, which has led to prolonged droughts in some areas and crop-destroying floods in others.