In a joint interview with Tony Blair, who was left looking visibly uncomfortable by her remarks, Sirleaf told the Guardian: "We've got certain traditional values in our society that we would like to preserve."
Liberian legislation classes "voluntary sodomy" as a misdemeanour punishable by up to one year in prison, but two new bills have been proposed that would target homosexuality with much tougher sentences.
Blair, on a visit to Liberia in his capacity as the founder of the AfricaGovernance Initiative (AGI), a charity that aims to strengthen African governments, refused to comment on Sirleaf's remarks.
When asked whether good governance and human rights went hand in hand, the British former prime minister said: "I'm not giving you an answer on it."
"One of the advantages of doing what I do now is I can choose the issues I get into and the issues I don't. For us, the priorities are around power, roads, jobs delivery," he said.
Over his 10 years as prime minister, Blair became a champion for the legal equality of gay people, pushing through laws on civil partnerships, lifting a ban on gay people in the armed forces and lowering the age of consent for gay people to 16.
A Catholic convert, he called on the pope to rethink his "entrenched" views and offer equal rights to gay people. But gay rights, he said, were not something he was prepared to get involved in as an adviser to African leaders.
With Sirleaf sitting to his left, Blair refused to give any advice on gay rights reforms. He let out a stifled chuckle after Sirleaf interrupted him to make it clear that Blair and his staff were only allowed to do what she said they could. "AGI Liberia has specific terms of reference … that's all we require of them," she said, crossing her arms and leaning back.
There have been no recent convictions under the sodomy law, according to the latest US state department human rights report. However, anti-gay activists have promoted two new bills which would take the legislation much further. One would amend the penal code to make a person guilty of a second-degree felony if he or she "seduces, encourages or promotes another person of the same gender to engage in sexual activities" or "purposefully engages in acts that arouse or tend to arouse another person of the same gender to have sexual intercourse", carrying a prison sentence of up to five years.
The second bill – drafted by the ex-wife of the former president Charles Taylor – would make gay marriage a crime punishable by up to 10 years in jail. Jewel Howard Taylor told the Guardian: "[Homosexuality] is a criminal offence. It is un-African." She went on to say: "It is a problem in our society. We consider deviant sexual behaviour criminal behaviour.
"We are just trying to strengthen our local laws. This is not an attempt to bash homosexuals."
The announcement brought unprecedented attention to homosexuality in a country where until recently gay people and lesbians lived in secret, but generally not in fear for their lives. Since Clinton's remarks, Liberian newspapers have published numerous articles and editorials describing homosexuality as "desecrating", "abusive" and an "abomination".
"Over the last six months, we've seen a worrying increase in anti-gay rhetoric, intolerance and indeed attacks on individuals fighting for the rights of Liberians in same-sex relationships," said Corinne Dufka, a senior researcher for Human Rights Watch in west Africa.
In the past month alone there have been at least six homophobic attacks in the capital, Monrovia.
One 21-year-old gay man, who recently left Monrovia to move to the countryside after some of his friends were threatened, said he now lived in fear of mob violence, a common occurrence on the streets of Monrovia. "You and your brother walking down the street, they may actually jump on you and beat you, kill you, and when they say: 'Oh they are gay, that's the reason we killed them,' nothing will come of it," he said.
Homosexuality is already illegal in 37 African countries. In Uganda, a bill proposing custodial sentences for homosexuality is still being considered, although it no longer contains the provision for the death penalty. Ten women were recently arrested in Cameroon accused of being lesbians, while in Nigeria, homosexual activities are punishable by up to 14 years in prison.
Sirleaf was awarded the Nobel peace prize last year for her work in campaigning for women's rights. The 73-year-old became Africa's first female president in 2006 and was elected for a second term last year. "If she tried to decriminalise the [current anti-gay] law it would be political suicide," said Tiawan S Gongloe, the country's former solicitor general. Without a majority government, Sirleaf desperately needs the support of other MPs to tackle other issues such as corruption, exploitation of the country's natural resources and mass youth unemployment, he said.
After 14 years of civil war that ended in 2003, Liberia is still one of the poorest countries in the world.
Gongloe also said the country was still not ready for a debate on gay rights. "Liberians need public education on the issue. Our society is not at that point yet to have a civil conversation on the issue," he said.
At an African Union summit earlier this year Ban Ki-moon urged African leaders to respect gay rights and to stop treating gay people as second-class citizens and criminals.
When pushed on the UN secretary general's comments, with Sirleaf at his side, Blair responded: "I'm not saying these issues aren't important, but the president has given her position and this is not one for me."