Members of a 3000-strong US-bound migrant caravan massed in a Guatemalan border town and prepared to begin crossing the muddy Suchiate River to Mexico Friday, in spite of US President Donald Trump's threats of retaliation.
The first members of the group began arriving in Tecun Uman on buses and trucks early Thursday, but the bulk of the caravan sloshed into town on foot in a downpour late in the afternoon and into the evening.
Before dawn Friday, the migrants decided to wait a few more hours for stragglers to arrive before heading to the border crossing.
Some planned to walk toward Mexican territory in a formation that put the men along the edges and women and children in the centre.
Others prepared to cross the river in rafts, the traditional way migrants enter.
Mr Trump has made it clear to Mexico that he is monitoring its response. He has threatened to close the US border if Mexico let the migrants advance.
Later, he retweeted a video of Mexican federal police arriving at the Guatemalan border and wrote: "Thank you Mexico, we look forward to working with you!"
Three weeks before US midterm elections, Mr Trump has seized on the caravan as a political winner for Republicans.