The United States says it has not played a role in recent moves by its anti-terror partner in East Africa, Djibouti, to expel as many as 100,000 illegal immigrants. The immigration crackdown follows warnings by Washington about possible terrorist threats on Western interests in Djibouti.

The Djiboutian government ordered the expulsion of the country's huge illegal immigrant population in July. The immigrants, who make up 15 percent of the tiny east African nation's population, were given until August 31 to leave. But authorities recently extended that deadline until September 15.

Djiboutian officials say the immigrants, who are mostly from neighboring Somalia, Ethiopia and Eritrea, are being expelled because they pose a security threat and are a drain on Djibouti's struggling economy.

But citing anonymous Djiboutian and Western sources, local and international media have also reported that Washington put pressure on the Djiboutian government to crackdown on illegal immigrants to better protect American troops stationed in the former French colony.

In May, a U.S. led counter-terrorism task force in the Horn of Africa established a temporary base in Djibouti. About 2,000 American troops are there taking part in combat and humanitarian missions aimed at preventing terrorists from gaining a foothold in the volatile region.

But the spokesman for the U.S. embassy in Djibouti, Chase Beamer, said reports that the United States influenced the Djiboutian government's decision to expel foreigners are not true. "The United States recognizes the sovereign right of every state to control its borders and to require that all persons be properly admitted and documented. However, the United States has played no role in the formation of the Djiboutian government's current policy," he said.

More than half of the 100,000 illegal immigrants targeted for expulsion have left Djibouti in recent weeks. But the U.N. refugee agency says it is having difficulty coping with thousands of others who have besieged a transit center in Djibouti.

Most of them are trying to apply for asylum and legalize their stay before the September 15 deadline. UNHCR says the people do not want to go home because the problems that caused them to flee their homelands are continuing. Those include the civil war in Somalia, a severe drought in Ethiopia, and political repression in Eritrea.