(AFP) - Liberian leader and football legend George Weah has conceded defeat to opposition leader Joseph Boakai after a tight presidential run-off, saying it was "time to put national interest above personal interest".

The latest and nearly complete results on Saturday showed Boakai leading with nearly 51 percent of the votes in Liberia, Africa's oldest republic, which was founded by freed American slaves.

"The results announced tonight, though not final, indicate that... Boakai is in a lead that we cannot surpass," Weah said in a speech on national radio late on Friday.

He said his CDC party "has lost the election but Liberia has won," adding: "This is the time for graciousness in defeat".

The 78-year-old Boakai lost to Weah, 57, by a large margin in the second-round of the presidential vote in 2017.

With more than 99.98 percent of the polling stations reporting after Tuesday's second-round vote, Boakai had garnered 50.64 percent of ballots cast to 49.36 to his opponent, according to the election commission.

The two finished neck-and-neck in the first round last month, with a national lead of just 7,126 votes for Weah.

The election six years ago of Weah -- the first African footballer to win both FIFA's World Player of the Year trophy and the Ballon d'Or -- had sparked high hopes of change in Liberia, which is still reeling from back-to-back civil wars and the 2014-2016 Ebola epidemic.

But critics have accused his government of corruption and him of failing to keep a promise to improve the lives of the poorest.

"We want development, we want schools," Mary Bee, a 52-year-old voter, told AFP.

The United States congratulated "president-elect Boakai on his victory and President Weah for his peaceful acceptance of the results".

"We call on all citizens to follow President Weah's example and accept the results," US State Department spokesman Matthew Miller said in a statement.

- 'Liberian people have spoken' -

Weah said he had spoken to Boakai "to congratulate him on his victory".

"The Liberian people have spoken, and we have heard their voice. However, the closeness of the results reveals a deep division within our country," Weah said in his speech.

"Let us heal the divisions caused by the campaign and come together as one nation and one united people."

Weah, who remains president until the handover of power in January, pledged to "continue to work for the good of Liberia".

It will be the second peaceful handover of power from one democratically elected government from another in two decades.

The elections were the first since the United Nations in 2018 ended its peacekeeping mission, created after more than 250,000 people died in the two civil wars in Liberia between 1989 and 2003.

International observers, including the European Union, have commended Liberia for holding a peaceful election.

Onekia M. Dwalu, a 29-year-old teacher, said the result "shows that people are tired and really want a change in this country".

For Weah backer James G. Yamah, a 28-year-old tailor, "The election was free and fair and we heard that from the president himself that the election was okay."

"I feel bad that we did not win, it hurts, but life has to go on and we have to put Liberia first," he said.

The Economic Community of West African States (ECOWAS) said the vote was "largely" peaceful but noted isolated incidents that led to "injuries and hospitalisations" in four provinces.

Clashes during the campaign left several dead before the first round and raised fears of post-election violence.

Around 2.4 million Liberians were eligible to vote on Tuesday and the turnout was roughly 66 percent, according to the electoral commission.

"I would like to commend the peace that we continue to see at all polling stations," said Nevers Mumba, head of the Electoral Institute for Sustainable Democracy In Africa (EISA) and the former vice president of Zambia.

But he noted: "We are a little bit concerned about the turnout. It seems to be almost a third of what we saw in the first election."

Boakai is an old political hand, having served as vice president to Ellen Johnson Sirleaf, Africa's first elected female head of state, from 2006 to 2018.

Liberia, home to around five million people, is one of the poorest countries in the world.

More than a fifth of the population lives on less than $2.15 a day, according to the World Bank.

© Agence France-Presse