Christian Aid is calling for a human rights-based approach to the migrant caravan making its way from Honduras to the US.
The Washington Post reports that 5,700 people departed from Mexico City on Sunday morning after staying in temporary shelters.
The newspaper said the migrants appeared to be heading for Tijuana 1,600 miles away, a town that sits just across the border from San Diego in the US.
President Donald Trump has claimed that gang members and terrorists are among the migrants, and has deployed thousands of troops to the southern US border.
Christian Aid said that most of the migrants are people fleeing their homes in Honduras because of violence there.
'Displaced, and unprotected by the State, they end up seeking international protection outside of the Northern Triangle Countries [Guatemala, Honduras and El Salvador],' it said.
According to Christian Aid's partner in the region, the Mennonite Social Action Commission (CASM), around a third of those fleeing are children, the elderly, pregnant women and people with disabilities.
'The situation is a humanitarian crisis that urgently needs a response,' CASM said.
'Most people in the caravan are walking, sometimes taking lifts offered on the road, these people are being injured, with wounds on the feet, children are suffering from diarrhoea, vomiting, sunstroke and fainting due to the hardships of the journey.'
CASM said a 'holistic and comprehensive human rights approach' was needed as it called on the Organization of American States to agree on a protocol to address the situation.
'This call to action is not only opportune but of utmost importance,' it said.
Christian Aid said it expresses solidarity 'with all migrants' and called upon states and international organisations to ensure that their rights are protected.
'Christian Aid has also called on the authorities to avoid mass deportations and abide by principles of humanitarian law,' it said.
'All countries have an obligation to ensure the safe passage of people, to protect the life and the rights of migrants, and to study each case individually.'
