Kenya’s Deputy President William Ruto has called on the United Nations to close the Dadaab refugee camp and relocate more than 500,000 Somalis.
Dadaab, near the border with Somalia, is the largest refugee camp in Africa.
On 2 April, Somali militants from the al-Shabab Islamist movement attacked a college in the Kenyan town of Garissa, killing 148 students.
But the head of the UN refugee agency UNHCR in Kenya told the BBC they had not been asked to close the camp.
Mr Ruto said UNHCR had three months to close Dadaab and make alternative arrangements for its residents – otherwise, Kenya would “relocate them ourselves”, he said.
Raouf Mazou, country representative for UNHCR in Kenya, said he heard about the government’s intentions in the news.
Dadaab was set up in 1991 to house families fleeing conflict in Somalia. Some people have been living at the site for more than 20 years.
Kenyan MPs and governors have previously accused al-Shabab of hiding out in the Dadaab camp.
Al-Shabab was also behind a deadly siege at the Westgate shopping mall in Nairobi in 2013.
Speaking on Saturday, Mr Ruto insisted Dadaab should be closed down and its residents moved back to Somalia.
“The way America changed after 9/11 is the way Kenya will change after Garissa,” he added.
Macharia Munene, professor of international relations at a Kenyan university, told the Reuters news agency that moving hundreds of thousands of refugees across the border would be “a tall order”.
But he said there were now safe areas within Somalia, from where al-Shabab militants had been chased out by African Union forces.
Kenya has also started building a 700km (440-mile) wall along the entire length of the border with Somalia to keep out members of al-Shabab.
“We must secure this country at whatever cost. Even if we lose business with Somalia, so be it,” said Mr Ruto.