Nana Akufo-Addo was sworn in as Ghana's new president on Saturday, in a ceremony attended by dozens of African leaders.
The 72-year-old former human rights lawyer defeated incumbent John Dramani Mahama in elections last month.
"I will not let you, the people of Ghana, down," Akufo-Addo wrote on his Twitter feed just after he took office. He also vowed to reduce taxes to boost the economy and declared that Ghana was "open for business again".
The new president took the oath of office at a ceremony in Independence Square in central Accra, marking the latest peaceful transition of power in the West African country.
More than 6,000 members of the public, dignitaries and heads of state were in attendance, including Nigerian president Muhammadu Buhari and Kenyan president Uhuru Kenyatta.
Akufo-Addo told AFP news agency that after smooth handovers of power in his home country and places such as Nigeria, leaders wanting to stay in office at all costs were "fighting the tide of history".
During the week of Akufo-Addo's election, beaten President Yahya Jammeh of The Gambia promised to challenge the results of elections that he had previously accepted.
Ghana's elections, which were held on December 7, came in the wake of a weak economy. The country was unhappy with the ruling party. Seven out of 10 Ghanaians believed that the country was headed in the wrong direction, according to the Ghana Center for Democratic Development.
Akufo-Addo has vowed to put Ghana "back on the path of progress and prosperity" after an economic slump under Mahama that led to an International Monetary Fund bailout.
This week, Mahama defended his record, saying his government had been up against "strong headwinds" that caused growth to slow, public sector debt to rise and the cedi currency to fall.
On December 31, Mahama had encouraged his citizens to support Akufo-Addo as his successor.
"I stand here today, Mr Speaker, holding the baton of leadership prepared to pass it on with pride, goodwill and determination to Nana Akufo-Addo," said Mahama in a farewell address.
Source: News agencies