The 73-year-old grandmother, Africa’s first democratically-elected president, managed to appease her opponents on the eve of her inauguration and the opposition Congress for Democratic Change recognised her win Sunday after a rocky election and weeks of negotiations.
Some 30 heads of state and representatives will attend the ceremony which kicks off at 11:00am (GMT and local) and hundreds had already gathered on the grounds of the Capitol Building, an AFP correspondent said.
A military parade followed by regional floats representing the country’s fifteen counties will take place later in the afternoon followed by several inaugural balls and receptions in different political districts.
Foreign Minister Toga McIntosh has said that a budget of 1.2 million dollars (950,000 euros) has been approved for the ceremony in what is one of Africa’s poorest countries.
Sirleaf’s domestic popularity has waned since she first came to power in 2005, with attitudes cooling when a 2009 Truth and Reconciliation Commission report named her on a list of people who should not hold public office for 30 years for backing warlord-turned-president Charles Taylor.
However she remains widely respected abroad for her role in reconstructing the nation shattered by a 14-year conflict.
Among those attending Monday’s ceremony is US Secretary of State Hillary Clinton who said Sirleaf “has done a remarkable job of rebuilding her country”.
“Liberia has been a close friend of the United States for so many years,” said Clinton upon her arrival in Monrovia.
“It is important because Ellen Johnson Sirleaf is the only female president in Africa,” she added.
Africa’s “Iron Lady” won a joint Nobel Peace Prize in October, just days before a first round of voting in presidential elections which the opposition said was riddled with fraud.
Congress for Democratic Change candidate Winston Tubman boycotted the run-off and called a protest march on the eve of the November 8 poll which turned violent and saw police open fire on his supporters, leaving up to four dead.
Sirleaf eventually won 90.7 percent of votes in the run-off, but turnout was low and the opposition refused to accept her victory.
While billed an opportunity to cement a fragile democracy eight years after the end of a 14-year conflict that killed 250,000 people, the elections showed the nation remained deeply divided.
After weeks of negotiations which stalled several times, Tubman called off a protest march planned for the inauguration and announced on Sunday: “We recognise that Madam Sirleaf is the president of Liberia.”
“Since the elections, we have been holding negotiations with the government on how to resolve the disagreement… and having had fruitful discussions, we feel confident that the CDC will be incorporated in the government,” he added.
Security has been tightened across the capital, with several check points set up along the highway leading to the country’s main Roberts International Airport, as UN military helicopters hover overhead.