"We believe that it is important for President-elect Morsi to take steps at this historic time to advance national unity by reaching out to all parties and constituencies in consultations about the formation of a new government," White House press secretary Jay Carney said in a statement issued for Obama Sunday.
"Millions of Egyptians voted in the election, and President-elect Morsi and the new Egyptian government have both the legitimacy and responsibility of representing a diverse and courageous citizenry," the statement said.
The United States believes "it is essential for the Egyptian government to continue to fulfill Egypt's role as a pillar of regional peace, security and stability," it said.
The United States "will stand with the Egyptian people as they pursue their aspirations for democracy, dignity and opportunity and fulfill the promise of their revolution," the statement said in reference to the revolt last year that led to the ouster of longtime ruler Hosni Mubarak.
Morsi has called for national unity and peace, and said he wants to expand ties with Iran.
In an interview with Iran's Fars News Agency, Morsi said Sunday he hoped to strengthen ties with Iran to "create a balance of pressure in the region -- this is part of my program."
Morsi's comments were reported by Fars Sunday, hours before he was officially declared the winner of Egypt's presidential election.
Diplomatic ties between Egypt and Iran were severed for more than 30 years but since Mubarak's ouster there appears to be a policy shift between the two countries, Israel Radio said.
In his first public speech on state television, Morsi vowed to preserve international accords and obligations and promised to be a president to all Egyptians, Ahram Online said.
"We will honor international treaties and agreements and will create balanced international relations based on mutual interests and respect. We will protect our borders and reject foreign meddling in our domestic affairs," Ahram Online quoted Morsi as saying.