PORT-AU-PRINCE, Haiti — The U.N. is turning to Bill Clinton as its emissary to chronically unstable Haiti, where the former president is popular but not the peacekeepers who have provided the nation's only real security for years.

United Nations Secretary-General Ban Ki-moon is expected to formally name Clinton on Tuesday as its special envoy to Haiti, the ex-president's spokesman Matt McKenna said.

U.N. peacekeepers have patrolled Haiti since 2004 and are in the process of training the country's underequipped national police to retake control — but some here consider the blue helmets an occupation force and have called for them to leave now.

Having Clinton as the U.N.'s public face in Haiti could temper such sentiment.

Clinton is still well-regarded here for using the threat of U.S. military force to oust a dictatorship in 1994, then sending Army troops and Marines to pave the way for the return of elected President Jean-Bertrand Aristide, who had been deposed in a coup.

Many poor Haitians — Aristide's power base — still long for their leader's return from exile after he was toppled a second time by a rebellion in 2004.

In March, Clinton toured the Haitian capital of Port-au-Prince with the U.N. chief to encourage investment after a year that saw a food crisis, destabilizing riots and four devastating tropical storms.

The following month, he attended a donors conference in Washington that resulted in pledges of $324 million for the struggling country.

Because of his marriage to U.S. Secretary of State Hillary Rodham Clinton, State Department lawyers must approve and review some of Clinton's international activities under an agreement between the U.S. Senate and the Clinton Foundation.