US President Barack Obama on Friday announced USD 3 billion in private sector aid for Africa and urged the Group of Eight (G-8) largest economies to follow suit. In a speech at the Chicago Council on Global Affairs\' Global Agricultural Development Initiative, Obama called it a \"moral imperative\" for the US to lead the fight against hunger and malnutrition in Africa, but offered no new federal financial pledges. However, the United States and other major donor countries \"will continue to make historic investments\" in development, the President said. \"Some have asked in a time of austerity, whether this new alliance is just a way for governments to shift the burden on to somebody else,\" Obama said of the private sector commitments. \"I want to be clear, the answer is no.\" Obama\'s announcement in Washington kicked off four days of international summitry. World leaders are gathering at Camp David, the presidential retreat in the Maryland mountains, later in the day for a summit of the Group of Eight leading industrial nations. Obama heads to Chicago on Saturday evening for NATO meetings. While much of the G-8 meetings will focus on Europe\'s mounting economic troubles, leaders will also hold a session on food security in Africa. Obama invited the heads of four African nation - Benin, Ethiopia, Ghana and Tanzania - to attend the meeting. The White House said the private sector pledges, along with commitments from donor countries to work with African nations on food security programs, could raise 50 million people out of poverty over the next 10 years.