The White House on Monday called on all parties in Ghana to accept the result of the presidential election, won by the incumbent but was claimed to be rigged by his rival.

White House spokesman Jay Carney described the election held on Friday as "successful" with a high voter turnout, saying "This is the sixth successful presidential and parliamentary election since 1992, and further demonstrates the people of Ghana's commitment to democracy and the rule of law."

"The United States encourages all parties to accept the results and to use the appropriate legal processes to resolve any electoral disputes," Carney said in a statement.

"The United States places a high value on its long-standing friendship and partnership with Ghana and the Ghanaian people," he added. "We look forward to strengthening our bonds by working with President Mahama and the people of Ghana to ensure prosperity, peace, and further democratic development of Ghana and the region. "

U.S. President Barack Obama has praised Ghana as a model for Africa in terms of both democratic practices and economic development.

Mahama, who took over the presidency in July following the sudden death of his predecessor John Atta Mills, was declared winner of the presidential election on Sunday.

The National Electoral Commission announced that Mahama won 50. 7 percent of the votes, beating his closest rival Nana Akufo-Addo from the New Patriotic Party (NPP) by a margin of three percentage points.

The NPP rejected the result, claiming the polls had been manipulated and rigged.