"It is the responsibility of the international community to fully supportSomaliaat this moment, to make sure the Somali story will be a story of success, to make sure Somalis go back," Guterres told a pledging conference in Brussels.

He reminded the conference, attended by EU foreign affairs head Federica Mogherini and top Kenyan and Somali officials, that Somalis were also among the hundreds of thousands of people who have crossed the Mediterranean to seek safety in Europe.

The EU pledged 60 million euros ($68 million) for the UNHCR, part of its own efforts to control the migrant crisis by getting countries of origin across the Middle East and Africa to take back their people.

War and upheaval inSomaliahave displaced more than two million people, with some 420,000 fleeing to Kenya while another 250,000 are in Ethiopia and about the same number in Yemen, according to UNHCR figures.

The UNHCR says it has helped 5,300 Somalis return home since end-2014 in cooperation with Kenya and Somalia.

Guterres said the numbers could now be increased after "tangible signs of stabilisation" in at least some parts of Somalia.

"We are now getting ready to move into the enhanced phase of this operation which will aim to assist 135,000 refugees to return to Somalia... (in) a voluntary repatriation in safety and dignity," he told the conference.

"It is in the interest of everybody thatSomaliasucceeds.Somaliawill then be a positive member of the international community... (making) an important contribution to the security of the region and the whole world," he said.

Pledges so far came to more than $105 million, he added.

Somali Foreign Minister Abdislam Omer said his government was "grateful" for the pledges and would work closely with its partners "to ensure the smooth return" of the refugees.

Kenya, which recently marked the second anniversary of a deadly mall attack by militants fromSomalia's Al-Qaeda-affiliated Shebab, has asked the UNHCR to help repatriate the refugees on its territory.