Central Americans traveling in a mass caravan broke through a Guatemalan border fence and streamed by the thousands toward Mexican territory Friday, defying Mexican authorities' entreaties for an orderly migration and U.S. President Trump's threats of retaliation.
Trump did not detail his military threat. Guatemala had closed its border gate and was standing guard with dozens of troops and two armored jeeps.
Officials in Mexico said anyone in the Honduran caravan who had proper documents could enter the country.
President Trump's watching his worst nightmare unfold - more than 1,500 immigrants marching from Honduras to the USA, and he's vowing our troops will stop them. if Mexico can't get the job done.
Mexico's ambassador to Washington, Geronimo Gutierrez, told Fox News that seven migrants had already made requests to receive refugee status in Mexico. In April, he said in a meeting with foreign leaders that the U.S.is "going to be guarding our border with our military".
Mexican authorities, in a bid to soothe Mr Trump's fury and to deter the migrants, without appearing to violate global law, have asked the United Nations to set up a migrant processing centre near its southern border.More news: Searches in the case of missing journalist
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Those who apply for refugee status will be vetted by United Nations officials at the immigration shelters on the border.
More than 3,000 migrants are demanding they be let into Mexico, and ultimately through to the U.S., with many heard chanting "We want to work!". Press Secretary Sarah Sanders issued a statement saying "while we are passionate about solving the issue of illegal immigration, we are not angry at one another".
The migrants say they organized for the long and hard journey on social media, but Washington suspects the group has been organized as a deliberate provocation.
Under pressure from the USA to stop the migrants, Mexico has sent federal police to the border, though they are not officially there to stop the caravan.
An estimated 10% of the population of Guatemala, El Salvador and Honduras have fled danger, forced gang recruitment and dismal economic opportunities.
"It was predictable, and it's also very close to the election", he said.
The latest focus is on more than 2,000 Hondurans who left last Saturday from the city of San Pedro Sula.
And the president-elect, Andrés Manuel López Obrador, has pledged to issue work visas for Central Americans in a bid to retain workers in the area rather than seeing them moving to the US.