CIUDAD JUAREZ, MEXICO - Dozens of Central American migrants who were forced to wait in Mexico for their asylum claims to be processed in the United Stated opted Tuesday to return to their home countries with the Mexican government's help, the foreign ministry said.

Sixty-six people from Honduras, Guatemala and El Salvador had been sent back to Mexico's Ciudad Juarez opposite El Paso, Texas, after requesting asylum in the United States, the ministry said in a statement, under a contentious U.S policy known as Migration Protection Protocols (MPP).

Mexico organized the return trip with the support of the U.N.-backed International Organization for Migration as part of its launch of a "temporary program of voluntary return" for migrants in northern Mexico, it said.

U.S. asylum cases can take months or years to be decided because of a massive backlog of immigration court cases. Even hearings can take months to be scheduled.

"The people want to go back to their places of origin, and want to leave this dream behind and go back to Honduras, Guatemala and El Salvador," said Javier Calvillo, director of Casa del Migrante, a local advocacy group assisting the return effort.

The people boarded large buses in the morning to head back home, according to a Reuters witness.

Mexico said three other Central American migrants who were not part of MPP also chose to return home.

More than 15,000 migrants claiming asylum in the United States after crossing the U.S.-Mexican border, most of them Central Americans, have been sent back to Mexico to wait for their cases to be processed since January under MPP, according to Mexican officials.

The program has been slammed by migrant advocates as well as asylum officers who say it could put migrants at risk by sending them for extended periods to live in some of Mexico's most violent cities.

Despite the outcry, U.S. authorities recently said MPP would soon be expanded to apply to migrants passing through five border cities, up from the existing three.