HARARE - Zimbabwe's President Emmerson Mnangagwa was on Monday sworn in for a second term after being declared the winner of last month's disputed election, as he promised to lift millions out of poverty.

Zimbabweans went to polls on Aug. 23 to elect a new president, parliamentarians and local council members, but the main opposition party described the results as a "gigantic fraud".

In his speech after being sworn in, Mnangagwa pleaded for unity in the aftermath of the polls, promising to revive the ailing economy.

"Responsive policies which begun in the first term of my presidency are on course to lift many out of poverty," Mnangagwa said.

Thousands of Mnangagwa's supporters, mostly bussed in from across the country, sang and danced as the 80-year-old walked into the National Sports Stadium alongside his wife.

He took oath of office in front of Chief Justice Luke Malaba who in 2018 declared Mnangagwa as winner following a constitutional court challenge.

"I stand as a president of all. I offer you individually and collectively, unity," Mnangagwa said.

Several African leaders, including South African President Cyril Ramaphosa, Mozambique leader Phillipe Nyusi and Congolese President Felix Tshisekedi attended the swearing-in ceremony, while Zambian President Hakainde Hichilema chose to stay away.

Mnangagwa's second term comes amid unrelenting economic challenges, with the Zimdollar having plunged 80% since the start of the year while international funding remains frozen.

Nelson Chamisa, the 45-year-old leader of the opposition Citizens' Coalition for Change (CCC) party, called for a new vote after his party alleged the election was "flawed" but did not challenge the result in court, clearing the way for Mnangagwa's inauguration.

Mnangagwa had encouraged the opposition to approach the courts but said the vote was valid and warned there would be a crackdown on anyone spreading chaos.

In its preliminary report, an observer mission by the southern African regional bloc SADC said the election fell short of regional standards and international standards while the European Union's (EU) observer mission said the polls happened under a "climate of fear".

The government was also criticised for the arrest of over 40 civic society organisation activists and alleged widespread voter intimidation in the countryside.

Although voting went on peacefully, polling was marred by massive delays in the deployment of ballot papers, leading to opposition accusations of voter suppression.

After being side-lined from the international community for over two decades, Zimbabwe has under Mnangagwa sought to re-engage erstwhile western partners.

In the absence of foreign funding, Zimbabwe's economic challenges are expected to continue as millions face an uncertain future.

Mnangagwa hinted that he will maintain the country's currency, the Zimdollar, despite its weakening against the U.S. dollar since its reintroduction in 2019.

"A national currency is indispensable. We can only grow our economy based on internal resources. Development and national prosperity in what we have is more sustainable and durable," Mnangagwa said.

(Reporting by Nyasha Chingono, Editing by Bhargav Acharya, Anait Miridzhanian and Ed Osmond)