Mexico City - Mexico on Wednesday said it plans to grant 20-day transit visas to a group of 180 Cubans who were chosen from thousands stranded in Costa Rica to continue on their long journey toward the United States.

The Cubans will have to leave Mexican territory after the permits expire, the National Migration Institute said, adding the visas were given for humanitarian reasons.

The Cubans' arrival is part of a pilot program agreed last month to start allowing the migrants to move toward the United States from Costa Rica, where they have been stuck since mid-November after Nicaragua shut its borders.

The first group, chosen out of an estimated 8,000 stranded there, flew to El Salvador on Tuesday, from where they boarded buses and arrived in Mexico on Wednesday.

The flow of migrants from Cuba has surged as the process of a detente between Washington and Havana stirs fears that preferential U.S. asylum rights for Cubans may end soon.

Central American governments will meet next Thursday in Guatemala to evaluate the first trip of Cubans and see if the transit program should continue, Costa Rican Foreign Minister Manuel Gonzalez said on Wednesday.

In upcoming meetings, diplomats are also expected to work out logistical details of how the migrants' travel will be paid for, the Mexican government has said.