PORT-AU-PRINCE, Haiti (AP) _ Former President Jimmy Carter, who averted a U.S. invasion by persuading Haiti's military leaders to step down, arrived Thursday to work on the next step in Haiti's experiment with democracy.

Carter said he planned to help prepare for peaceful elections and assess progress on security and economic issues. Carter oversaw the December 1990 presidential election that Jean-Bertrand Aristide won by a landslide.

The next major democratic test for Haiti is scheduled for June 4, when the first round of legislative and local elections takes place. Presidential elections are set for December.

Carter, accompanied by his wife Rosalynn, was to be joined Friday by Sen. Sam Nunn, D-Ga., and retired Gen. Colin Powell, former chairman of the Joint Chiefs of Staff. All three were instrumental last fall in inducing the departure of Haiti's military leadership, leading to the unopposed arrival of the U.S.-led multinational force.

They will meet with Aristide, Haitian government officials and political party leaders, among others. Also on the agenda during Carter's three-day visit is a review of the international aid effort in Haiti.

Carter's visit coincides with a scaling down of U.S. forces from a peak of 21,000 troops to 3,000 by the end of the month. Americans are expected to comprise slightly less than half of a 6,000-member U.N. force that takes over from the American-led force on March 31.

Aristide's government didn't send a representative to greet Carter at the airport, and someone had painted red graffiti in a square in the capital demanding that he go home.

Although Carter's September negotiations forestalled a U.S. invasion and likely saved thousands of lives, some Haitians resent the fact that Haiti's military rulers were allowed to stay in power for almost a month and then leave for exile.

Carter was upbeat as he stepped from the plane.

``I've always been welcomed when I return to Haiti _ this time by President Aristide, who invited us to come, and also, I understand, by a graffiti artist who in red paint wrote words of welcome,'' Carter said with a smile.

Lt. Gen. Raoul Cedras and Brig. Gen. Philippe Biamby went to Panama and Police Chief Michel Francois went to the neighboring Dominican Republic.

Several Haitian youth groups and neighborhood political organizations spoke out against Carter's visit, but a threatened demonstration at the airport did not materialize.

Venel St. Trouice of the Avenue Pouplard Youth Movement said Thursday that U.S. soldiers arrested a colleague as he was painting graffiti in a downtown neighborhood. An Army spokeswoman could not immediately confirm the arrest.

The Haitian army and its attaches killed more than 3,000 people in the three years following Aristide was overthrown in a coup in September 1991. After his return last Oct. 15, Aristide vowed to cut the army from 7,500 to 1,500 soldiers and establish a separate police force.

On Monday, he dismissed the army high command, ordering the early retirement of 43 officers, including the country's only four generals.

U.S. officials said most of the retiring officers were disreputable and potential dangers to democracy.

Political violence has declined dramatically since the multinational force arrived on Sept. 19, although common crimes have increased. A new police force is being trained by international police monitors.