During a two-day conference in Switzerland, more than 40 countries backed the Lausanne Call for Action, committing to concrete actions towards humanitarian demining in Ukraine, the organisers said.
"Ukraine has become the most mined country in the world," Ukrainian Prime Minister Denys Shmyhal told the conference.
He said that since Russia's February 2022 invasion "about a quarter" of Ukraine had become covered with mines and unexploded bombs.
"The scale of this challenge is truly massive," he said.
"We are talking about an area of approximately 140,000 square kilometres -- nearly three times of size of Switzerland."
He pointed to expert estimates that "up to 9,000 civilians could lose their lives" if action is not taken to clear away the mines.
Swiss Foreign Minister Ignazio Cassis stressed the urgency. "Without humanitarian demining, you do not have agricultural production, you cannot feed people, you cannot let children play, you cannot build industry," he told a press conference.
Representatives promised on the first day of the Lausanne conference to help provide "swift and safe rehabilitation of agricultural areas", according to a Swiss statement.
They also vowed to support "the economic and social reintegration of victims with disabilities" and "the promotion of international cooperation between the various partners active on the ground".
They committed to supporting local manufacturing of demining tools in Ukraine, as well as exchanging experience and knowledge to foster "innovative methods and technologies that increase the effectiveness of mine action" globally.
The World Bank has estimated that demining Ukraine will cost around $37 billion -- a figure Shmyhal said was "likely to grow".
He stressed the need for more demining machines, pointing out that they in a single day could carry out the equivalent of 100 days of manual labour.
Since a first Ukraine demining conference was held in Croatia last year, Kyiv has seen its number of demining machines swell from 32 to nearly 100, Shmyhal said. Several times that number were needed, he added.