Onlookers from the US side view the US-Mexico border wall. The Central American migrant caravan on Friday received warning that its chances of entering the US were "almost nil." After traveling thousands of kilometers to Tijuana, migrants face the bleak reality of near-certain failure. Photo: AP

More than 1,500 members of a migrant caravan that set off toward the US border from southern Mexico in October have been issued documents to regularize their stay in Mexico, the migration authority said on Tuesday.

The National Migration Institute (INM) said it had given 1,574 foreign nationals migration cards and ensured they could work in Mexico since the caravan set off on October 23.

Enduring adverse weather and under pressure from officials to give up, the caravan containing many women and children has made slow progress through southern Mexico, and on Tuesday moved into the Gulf state of Veracruz from neighboring Oaxaca.

Reuters witnesses estimated up to 1,500 people entered Veracruz. Organizers of the caravan put the figure at 2,000. About 3,000 people were in the caravan when it set out, though some estimates since then have put the number higher.

Overnight, the caravan stopped in the municipality of Jesus Carranza on Veracruz's border with Oaxaca.

Hector Martinez, a senior INM official, denied that authorities were trying to block the caravan's progress, but again urged its members to accept documentation to stay in Mexico.

The bulk of the people in the caravan are Central Americans, as well as people from the Caribbean who are seeking to escape economic malaise and security problems in their homelands.

Organizers of the group said a new caravan with more Haitians could depart from the southern Mexican city of Tapachula on Thursday.

Reuters