Experts in Ethiopia say up to 250,000 mines lie along its contentious border with Eritrea - undetected until a child or farmer stumbles across them.
However, there may be four times that number littered across the huge Horn of Africa country.
"It's one of the most infested countries in the world," UNICEF Country Director for Ethiopia Bjorn Ljungqvist said. "It comes from a long history of war, starting from Italian occupation."
As a result, some 364,000 Ethiopians have been uprooted from their homes and villages because mines have made it unsafe for them to stay, UNICEF says.
Ethiopia's announcement at the start of the five-day Nairobi Summit on a Mine Free World comes seven years after it and 122 other nations signed a landmark anti-personnel mine ban treaty in Ottawa, Canada in December 1997.
"We believe the Ethiopian ratification will give the endeavour toward a total ban on antipersonnel mines a new emphasis and open a new era of cooperation among the countries of the Horn of Africa," Adulkadir Risku, a diplomat from Ethiopia's foreign ministry, told the delegation.
Around 250,000 mines lie on
Ethiopia's border with Eritrea
The Nairobi meeting is technically a treaty-mandated review of the progress made since the ban went into force in 1999.
Organizers say the top goals are to encourage new financial commitments from donors and member nations, to push others to join and to ensure that the nations who are to have destroyed and cleared all of their mines by 2009 do so.
On the sidelines of the conference, US actor Danny Glover blasted his country for failing to sign a pact to eliminate landmines after he visited child victims of landmines in Ethiopia.
Annan will only address the
conference by video
At the same time Glover, a vocal activist on child issues and a newly appointed Goodwill Ambassador for the United Nations Children's Fund (UNICEF), pledged to do everything in his power to help children affected by war.
"After talking to children I feel a sense of embarrassment and anger that my own country has not signed the landmine treaty," said Glover, who is probably best known for his role as Sergeant Roger Murtaugh in the "Lethal Weapon" series.
"I think the US abandonment of the Ottawa Convention sends a bad message to the rest of the world," he told a reporters in Geneva, where the 57-year-old is spending the night en route back to the US after his Ethiopia trip.
A key effort of the campaign will be to boost aid to landmine survivors, which supporters say has fallen disappointingly since the treaty went into effect.
"Once a landmine is gone, it's out of the ground and you never hear from it again. It's harder to listen to a survivor throughout their whole lives," 1997 Nobel Peace Prize Laureate Jody Williams of the International Campaign to Ban Landmines told reporters.
But the meeting has less of the diplomatic star-power than it had during the founding conference in Ottawa, which gave the treaty its nickname. UN Secretary-General Kofi Annan, present at the 1997 meeting, is only scheduled to address the conference by video, and only a few nations are sending high-level delegates.
"They feel that Ottawa is in good hands," said Wolfgang Petritsch, the veteran Austrian diplomat who is the summit's president.
Of 144 nations in the treaty, 108 have sent delegates, as have 23 nations outside of the treaty. Noticeably missing are official representatives from Russia and the United States, who have not joined. China, the other major military power that has not joined, is attending as an observer.
"Despite the fact that military powers like China and the US are not parties, a powerful norm is being set in place because most nations are complying," Williams said.