U.S. President Barack Obama on Sunday called Egyptian President-elect Mohamed Morsi, pledging continued U.S. support for the transition in the Arab country.

Extending his congratulations to Morsi, who as the candidate of Egypt's Muslim Brotherhood was declared winner on Sunday of the presidential run-off, Obama stressed that "the United States will continue to support Egypt's transition to democracy and stand by the Egyptian people as they fulfill the promise of their revolution."

"He emphasized his interest in working together with President- elect Morsi, on the basis of mutual respect, to advance the many shared interests between Egypt and the United States," the White House said, noting the pair affirmed their commitment to advancing the U.S.-Egypt partnership.

On his part, Morsi welcomed U.S. support for Egypt's transition, the White House said.

As the first elected president without military background in Egypt, Morsi faces big challenges ahead, as he will take office without a new constitution and parliament, while the ruling Supreme Council of the Armed Forces, despite its pledge to hand over power to the new president by the end of June, has sought to consolidate its power and limit the president's power.

In his separate phone talks with Ahmed Shafiq, Morsi's rival in the presidential polls and former Egyptian premier, Obama encouraged the general to continue to play a role in Egyptian politics by supporting the transition process and working to unify the Egyptian people.

Washington maintained a close relationship with Egypt when Hosni Mubarak was president. The Obama administration is worried about the prospect of its relations with the most populous Arab country since Mubarak was ousted early last year in anti- government protests.

Egypt is the other country besides Jordan to have signed a peace deal with Israel, the key U.S. ally in the Middle East region.