WASHINGTON — US lawmakers on Tuesday called for a push to boost exports to Africa, saying that both sides would benefit if the United States sells more products to the continent's growing middle class.

Lawmakers from both major US parties teamed up to introduce bills in the House of Representatives and Senate that would set a goal of expanding US exports to Africa by 200 percent over the next decade.

The United States is a major donor to Africa and takes in one-fifth of its imports, but trade in the opposite direction has slipped in recent years with $21 billion worth of US exports to sub-Saharan Africa in 2011.

Representative Chris Smith, a Republican who co-sponsored the House bill, said that the trade drive would create US jobs and help the United States step up its presence in Africa at a time of growing Chinese involvement.

"Some have expressed concern that such an expansion of US exports to Africa could flood African markets and damage their economies," Smith said at a congressional hearing.

"However, many of these US exports, such as in the agricultural sector, will enable African producers to become more efficient and profitable and create jobs for their workers as well," he said.

The bill would require that 25 percent of US trade financing be devoted to Africa, create a new position of US-Africa trade coordinator, and encourage African American businesses to be active on the continent.

Representative Bobby Rush, the Democratic co-sponsor of the bill in the House, voiced hope that the effort would create jobs in his district in Chicago which has more than 60 percent youth unemployment.

Rush said he saw "the expansion of the American marketplace to Africa as being not only an opportunity to help the growing middle class in Africa, but also to help expand" jobs at home.

Testifying before the committee, Johnnie Carson, the assistant secretary of state for Africa, said: "It is my firm belief that Africa represents the next global economic frontier."

But Carson warned that many African nations needed to do more to encourage investment, including fighting corruption, improving infrastructure and making regulations more efficient.