Migrants travelling in a caravan through southern Mexico have rejected a proposal by Mexican President Enrique Pena Nieto that they apply for refugee status in the country and obtain benefits.

Coordinators of the caravan read out the president's plan called "You are at home." Migrants shouted "Gracias!" but "No, we're heading north!"

Activist Irineo Mujica of the People Without Frontiers group is supporting the migrants in the caravan. He told the group that 80 per cent of those who apply for protective status in Mexico would be rejected and deported.

He asked who wanted a dialogue when they arrive in Mexico City, and a sea of hands shot up.

Mujica accused immigration officials of trying to scare them.

The vote took place Friday evening after the caravan arrived in the southern city of Arriaga in Chiapas state.

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Mujica said the caravan would be on the move again Saturday at 3 a.m. toward Zanatepec, about 60 kilometres away in Oaxaca state.

Pena Nieto announced the launch of what's called the "You are at home" plan Friday in an address directed at migrants. He said migrants would be able to access medical attention, schooling and jobs.

To qualify, they must be in the southern states of Oaxaca or Chiapas; the caravan is currently in the latter. Migrants must also apply for refuge with the National Migration Institute.

Pena Nieto said the plan "is only for those who fulfil Mexican laws and is a first step toward a permanent solution for those who obtain refugee status in Mexico."