People forced to flee their countries by natural disasters find themselves in a legal vacuum where they are considered neither refugees nor migrants, Norway and Switzerland said Tuesday, as they launched an initiative aimed at protecting them.

"Forced displacements in the context of natural disasters is a reality," said Walter Kaellin, envoy for the new Nansen Initiative, calling for "a more coherent and consistent approach at the international level" to help such "environmental refugees."

Speaking alongside Switzerland's head of humanitarian aid, Manuel Bessler, and Norway's representative to the United Nations in Geneva, Steffen Kongstad, Kaellin said floods, wind-storms, earthquakes, droughts and other natural disasters forced nearly 15 million people to flee their homes last year.

And more than 42 million people fled from such disasters in 2010, added Kaellin, a constitutional law professor.

While most of these people are displaced within their own country and many can return after a limited period of time, those who flee across borders face an uncertain future.

"It is unclear whether and under what circumstances such people should be admitted (into a second country, and) it is unclear to what extent they are protected against being sent back into dangerous situations in their country of origin," Kaellin said.

It was also unclear which international aid agencies should be responsible for stepping in and helping them, he said.

Kenya's minister of state for immigration, Otieno Kajwang, hailed the initiative, telling the diplomats his country had learned the hard way how natural disasters can cause a refugee crisis.

Pointing out that some 200,000 Somalis fled into Kenya's Dadaab camp last year amid the worst drought in the region in 60 years, he stressed the need to "urgently address... the impacts that are caused by drought and the consequent displacements."

The initiative is named after Fridtjof Nansen, a Norwegian Arctic explorer and the UN's first High Commissioner for Refugees.

It will set up a secretariat at the UN complex in Geneva on November 1 and plans to start hosting regional meetings in the areas most affected by natural disasters, such as the Horn of Africa, Central America and the South Pacific.

The initiative aims to develop an international consensus around how to handle the problem through dialogue with the affected countries, as well as with international organisations like the UN's refugee agency and the International Organisation for Migration, Kaellin said.